300 PRC Custom Build: Chambering and Machining the Barrel

Рет қаралды 316,927

4 жыл бұрын

Full Story: ultimatereloader.com/2019/09/...
Gordy Gritters / Fred Zeglin Book: amzn.to/34HDe6D
UR T-Shirts: bit.ly/2UEAkgW
UR on Patreon: / ultimatereloader
Important notes:
- See chapter markers below
- This is a high-level overview for this particular project
- I am not teaching lathe operation in this video (see Making with Metal videos for that)
- There are 6 rifle chambering projects in the hopper, will be showing different things each time.
- Future videos will break down each process for chambering a rifle (individual stories)
0:10 Introduction, resources, background
4:00 Outline of components and process
6:20 Cutting down barrel blank (breech end)
7:00 Initial dial-in, facing, pre-drilling
8:18 New barrel dial-in technique
10:26 Dave Manson reamer, bushings, Go/No-Go gauges
10:57 Boring pre-drill, checking for runout
11:36 Turning tenon
12:54 Cutting threading relief
13:49 Threading the tenon
15:35 Checking for thread fit
15:57 Indexing barrel and action (barrel internal curvature)
20:17 Finished tenon, chambering setup
21:13 Precision Matthews PM-1440GT lathe performance/alignment
21:33 Pressure flush vs manual flush reaming
22:05 Viper's Vennom oil, starting chambering
23:18 Hawkeye Borescope - inspecting chambering progress
24:25 Monitoring chambering depth
24:48 Final chambering cuts and checks (last 0.010")
25:17 0.002" Go Gauge shim (tape)
26:43 Chamfering the chamber opening, polishing the chamber
27:44 Cutting barrel down (muzzle end)
28:04 Muzzle threading quick overview
29:48 Installing barrel
32:21 Checking headspace
33:33 Conclusion
-------------------------------------------
Ultimate Reloader LLC / gavintoobe Disclaimer:
You alone are responsible for the safety of yourself and your property.
Check local and state laws before undertaking any activity involving possessing, transporting, and shooting firearms. Check local and state laws before attempting to load ammunition or perform any modifications to a firearm. Always abide by the law. Always practice gun safety.
The content on this channel (including videos, ammunition reloading data, technical data, comments, and any other information contained within) is for demonstration purposes only.
Do not attempt any of the processes or procedures shown or described in this video or on this KZfaq channel (gavintoobe).
Any reloading data supplied on this KZfaq channel (gavintoobe) or in this video, including any comments from viewers and readers must be assumed to be in error.
Always consult at least three sources of manufacturer's ammunition reloading data before reloading your own ammunition.
Do not attempt to repair or modify any firearms based on information found on this KZfaq channel or in this video.
Gunsmithing procedures should only be performed only by a licensed gunsmith.
Ultimate Reloader, LLC can not be held liable for any harm caused to any individual or any personal property related to activities, procedures, techniques, or practices described in whole or part on this KZfaq channel (gavintoobe) or in this video.
By watching this video in whole or in part, you agree that you alone are solely responsible for your own safety and property as it pertains to activities, procedures, techniques, or practices described in whole or part on this KZfaq channel (gavintoobe) or in this video.
-------------------------------------------
Ultimate Reloader LLC / gavintoobe Material Connection Notice:
The following Ultimate Reloader partners are featured in this video:
- Hornady
- Benchmark Barrels
- TriggerTech
- MDT
Ultimate Reloader partnerships involve one or more of the following:
Product supplied for evaluation + testing + features in videos/articles, paid advertising and promotions, engineering and product development services, scientific testing and evaluation, external media production and related marketing services.
Ultimate Reloader LLC is committed to publishing subjective and data-driven information+insights related to products whether it be favorable or unfavorable or both.
For more information about Ultimate Reloader partnerships, please visit: ultimatereloader.com/about

Пікірлер: 313

@Ultimatereloader 2 жыл бұрын

Interested in an Ultimate Reloader custom rifle? Sign up on the list here: ultimatereloader.com/rifles/

@stephenland9361 4 жыл бұрын

"Always measure, always validate, verify... some mistakes are very difficult to correct later..." I'm a retired family doc. I recall assisting a General Surgeon with a major and critical abdominal operation. I was about to make a critical mistake but he caught me and then gave me one of those 'pearls of wisdom'. He said, "In surgery, there are two kinds of mistakes. The kind you can recover from and the kind you cannot recover from." You really, really want to avoid the second kind.

@skylershupe6226 2 жыл бұрын

I’m a machinist and I work in a world class machine shop and I can tell you some of the stuff he is talking about isn’t novice. And his machinery and tools that he has are extremely expensive

@ronalexander4955 5 ай бұрын

I was a machinist with 13 years before engineering school, I wouldn’t consider myself a high end machinist, and I agree totally.

@cs_yt 4 жыл бұрын

Can't imagine the satisfaction (and terror) of closing the bolt with the taped go gauge. Good Job! Looking forward for the rest of the series.

@Ultimatereloader 4 жыл бұрын

Well said :) It's a bit of suspense...

@BrandonHaynesGolf 3 жыл бұрын

I’ve been a machinist for 15 years now and I love guns. This is the ultimate nerd porn!!

@dirtpile 4 жыл бұрын

I need the book "Chambering Rifles For Dummies". In awe at the patience and precision you have!

@russellguyton3109 3 жыл бұрын

😂😂

@jeremydoblinger3609 3 жыл бұрын

One of the best feeling is a perfect surface finish on a part.. and also having it come out rite months number your shooting for.

@nathanielgray4235 2 жыл бұрын

Great work Most will never understand this level of work

@Veektohr 4 жыл бұрын

Just stumbled on this. What a great in depth video. Thanks!

@milo555100 10 ай бұрын

I want to do this. I have about 5 or 6 different builds in mind. Thank you for your content. Excellent.

@rifleshooterchannel208 4 жыл бұрын

Must be an amazing feeling to build a rifle from basically the ground up like that.

@Ultimatereloader 4 жыл бұрын

Yes, especially when things turn out "just right" :) :)

@rapidrrobert4333 4 жыл бұрын

Ground (as in earth) up? Are you kidding?

@rapidrrobert4333 4 жыл бұрын

@@rifleshooterchannel208 ... Buying parts and assembling them is not building.

@rifleshooterchannel208 4 жыл бұрын

RapidRrobert Thanks for your opinion.

@Mr79dream 4 жыл бұрын

@@rapidrrobert4333 we are not even allowed to do that :-(

@gw9853 4 жыл бұрын

Second time I've watched this. Amazing craftsmanship. German precision tolerances right there! Great job.

@dragonflyfab9703 2 жыл бұрын

Precision has no nationality. Thats all advertisement.

@hernandovillamarinbuenaven7476 2 жыл бұрын

Imperial measures still rule in America, though. I stil get headaches when someone talks metric, in spite of conversion tables / formulas.

@highflyer13131 4 жыл бұрын

Wish I had a great machine shop like that. I would live to give this a whirl.

@richlovin2173 4 жыл бұрын

An excellent tutorial on chambering a barrel the right way. Thanks a lot!

@Ultimatereloader 4 жыл бұрын

Thanks Rich!!!

@Chrisbuildsstuff247 4 жыл бұрын

He’s talking to me like I can afford this equipment and make these decisions haaaaa. I’m just here cause I love guns

@stevepuyear2738 2 жыл бұрын

😅😂🤣Me too!

@lnaesll 3 жыл бұрын

You should look into cutting the threads in reverse. You flip the tool over and cut in reverse. Then you don’t have to work about stopping the tool in a certain spot. Ever since I learned that I’ve never looked back.

@DusToDeath 4 жыл бұрын

Wow!.....just wow! Great job! Can't wait to see this thing shoot

@Ultimatereloader 4 жыл бұрын

Thanks! Lots more content coming...

@MichaelBrown-um8qc 2 жыл бұрын

My guy , put indicators on the reamer holder & we watched 👀 so cool & confidently showing the raw proof of accuracy & detail 😊 Dave made my go / no-go s, tighter to my request . Yes dave's finish reamers always leave great finish👍 . & Cuts many barrels 👍👍

@planeiron241 4 жыл бұрын

Bravo bravo great vid..... I like justa little tension on the go gauge at the bottom..makes ething safe and then you know it's good

@archangel20031 4 жыл бұрын

High speed shooting systems did a chambering video with comments disabled and it sucks as he only used one reamer and that means he used a rough reamer to finish ream, or used a finish reamer to rough and finish and nobody can ask him any questions! This guy explained it! Subscribe!

@trleith 2 жыл бұрын

I'm a rank beginner. I've used the RCBS Precision Mic and the "lightly crimp a bullet unreasonably long in a fire formed case, inking it up and closing the bolt on it" method. I like the latter much better. I can see where taking the extractor off the bolt and popping the assembly out with a rod could be helpful, especially without the Locktite. I was worried about the bullet moving when I removed it, and it did. But I could see where it had scraped off the ink, so I knew it happened and could try again. When I got the same answer three times I called it good. I like the Locktite optimization; it'll save me that problem. Setting the ogive .020 off the lands instead of about .090 helped a $350 rifle shoot pointy bullets 300-yard-hunting-well. It did ok with round nose bullets, but pointy ones gave more of a pattern than a group.

@williamjohnson2896 4 жыл бұрын

As I get close on threading I always hit the crest of the thread lightly with a file to remove the burr, keeps me from thinking I need to make another pass when I really don't. A good deburring pad is a nice touch on the final.

@Ultimatereloader 4 жыл бұрын

Same here!

@triggerguard1 3 жыл бұрын

@@Ultimatereloader Cratex is your friend. Thank me later.

@Ultimatereloader 3 жыл бұрын

@@triggerguard1 Thanks- been meaning to pick up some sticks since I saw them at Gordy Gritters' precision rifle building class...

@triggerguard1 3 жыл бұрын

@@Ultimatereloader Good deal. Started using that on threads about 30 years ago.

@isaiahyennie1583 4 жыл бұрын

Nice job, just a helpful tip. Use the saddle as a stop for the tailstock during chambering, so that you dont have to find the shoulder every time. I usually ream, back the tailstock off .050" loosen the tailstock and pull reamer out, clean, lubricate, push tailstock up against the saddle and turn to my last known number on the tailstock, usually within a few thou. T

@MichiganDeerHunter1 4 жыл бұрын

It's been a long time since I've done any turning work. This video makes me miss intense focus like you mentioned. Well done.

@Ultimatereloader 4 жыл бұрын

Thanks! Perhaps you can pick up a lathe for the garage to revisit your days of turning? :)

@jays2002 4 жыл бұрын

Excellent, as usual.

@rtrapper4life 4 жыл бұрын

Starting to look like something now 👍

@robertlunnar8260 Жыл бұрын

Great video lots to look forward to 👍👍

@floridamike75 4 жыл бұрын

Absolutely amazing!!!

@brockgarrison3617 4 жыл бұрын

Best build video on the tube

@Ultimatereloader 4 жыл бұрын

Thanks Brock!

@larrysperling8801 4 жыл бұрын

very nice video. i have been chambering rifles for over 40 yrs and i dont have half your toys, i'm jealous

@jakejacobson2999 Жыл бұрын

Your channel has got me so interested in gunsmithing that I am strongly considering getting my type seven. This probably sounds stupid but I honestly didn’t even know that gun smiths would actually make their own barrels lol I thought that was the only part that they would maybe just have to buy and they might make everything else but yeah very cool

@btramm1980 4 жыл бұрын

Hello there. Great job with the chambering! Did you bore away the lands in the neck area to prevent chatter like in Gordy's book? if so what boringbar did you use. One probably needs a small one to fit in the bore and long enough to reach to the front of the neck. Im having trouble finding one that will work. Thanks

@blacksand9805 4 жыл бұрын

I've got the same book, very interesting. I wonder what kind of accuracy you'll get with this caliber and such action+barrel quality

@tonydevich7937 Жыл бұрын

That's a good way to check check and recheck

@trophyadventures6258 2 жыл бұрын

This is awesome! Love the shop brother. New Sub 👍🏼

@justinromer6128 4 жыл бұрын

Love these videos.

@prozbroyu 4 жыл бұрын

Great video, absolutely must to see!

@Ultimatereloader 4 жыл бұрын

Thanks!

@zoidelux 4 жыл бұрын

Awesome content and advice, thank you for sharing, especially the barrel crush info, I'll have to revisit this video before I chamber my first barrel. I also have the gordy DVD and have listened to advice from other gunsmiths that learned from Gordy, and they're basically the best gunsmiths around for chambering. Just curious, could you also post the full length video of your chambering job? Maybe I'm weird but I'd like to see the entire process, even with or without commentary or even with long pauses changing tooling out, it's very entertaining, it would be awesome to see every step and subtle details! I understand some people would be bored to watch raw long footage format but some would really love it as I think a lot can be learned from seeing the entire process, kinda like how Gordy's or viper's videos are..

@bradb.4570 2 жыл бұрын

I would love to see more videos like that, I really want to chamber .223 in a barrel blank, and try and make my own receiver and bolt 🤷🏻‍♂️, who knows if I will ever succeed, but I think I have to try

@justinberwick2827 4 жыл бұрын

Very informative video. Keep them coming.

@Ultimatereloader 4 жыл бұрын

Thanks Justin!

@ocean374 4 жыл бұрын

Nice project great job came out awesome

@Ultimatereloader 4 жыл бұрын

Thanks!

@jayny5472 4 жыл бұрын

Great action 👍

@FrankWolfPower Жыл бұрын

Wow, so much good info !!!

@Ultimatereloader Жыл бұрын

Thank you, I've really had fun putting these stories together!

@jassonco 4 жыл бұрын

Excellent!

@daphoosa 2 жыл бұрын

When I see things like this, I miss my machinist days. Maybe some day I'll have room for a real shop.

@raywhitehead730 2 жыл бұрын

Impressed! Yourself education is coming along well.

@isoae4169 2 жыл бұрын

Good job

@bradleytyrrell4417 4 жыл бұрын

Love watching gunsmithing video's and builds awesome

@Ultimatereloader 4 жыл бұрын

I love doing this stuff! Glad you enjoyed watching.

@bradleytyrrell4417 4 жыл бұрын

@@Ultimatereloader can't wait for more videos they are very informative

@YaketyYakDontTalkBack 4 жыл бұрын

Awesome video man.

@Ultimatereloader 4 жыл бұрын

Thanks man!

@mxcollin95 2 жыл бұрын

I’m no gunsmith (although I wish I was) but I’m wondering why you wouldn’t want to thread the action on and tighten to a specified torque as opposed to just going with what you feel is tight enough? By the way, I am really, really impressed with your level of machining, devotion to precision and your video presentation skills! Absolutely top notch and the best I’ve seen on KZfaq so far in terms of gunsmithing! Definitely looking forward to all of your future content. 🤙

@40motomike 3 жыл бұрын

That PM 1440GT. what options did you get or that it comes with? I didn't see anywhere it mentions that digital read out. Was that additional? Looking at one myself currently!

@mmelgoza1983 4 жыл бұрын

Fantastic!!!

@archangel20031 4 жыл бұрын

On my AK63-D the barrel would bottom out and there was still too much head space. I ended up cutting a chamfer on the OD of the chamber end of the barrel letting it slide in just enough to head space correctly leaving a slightly firm resistance to turn the bolt home, (as per Russian specifications there is a torque applied to turn the bolt on a perfectly chambered go gauge) so it chambers and fires both brass and steel cased ammo as expected.

@tahcogunworks 4 жыл бұрын

Awesome work.

@Ultimatereloader 4 жыл бұрын

Thanks Tim!

@scottjacobs7341 4 жыл бұрын

Awesome Gavin

@Ultimatereloader 4 жыл бұрын

Thanks Scott!

@Chrissers2010 4 жыл бұрын

I was asking you earlier today about your lathe (on the "Precision Matthews PM-1440GT..." video). This 300 PRC chambering video is a great testament to the precision of your lathe on a real project! I really appreciate your attention to detail and your thorough explanations.

@Ultimatereloader 4 жыл бұрын

Thanks Jim! If you were close by I'd offer to take you out for a beer to talk lathes :)

@Chrissers2010 4 жыл бұрын

@@Ultimatereloader That would be cool. I'm not terribly far away in Roseburg Oregon, with family in Western Washington we see every couple years. Are you a hunter? I post a lot on the Eastmans forum under Umpqua Hunter. I'm on Facebook too.

@Ultimatereloader 4 жыл бұрын

Jim- send me a message on FB!

@Chrissers2010 4 жыл бұрын

@@Ultimatereloader Will do.

@tobiastorsi 4 жыл бұрын

Amazing. If i could i would do exactly what you do. You are living a dream!!

@Ultimatereloader 4 жыл бұрын

Thanks Tobias! I love my job :)

@alexisdauverne3359 4 жыл бұрын

Hello everyone, after multiple watching, I’m asking myself about the dial indicator seen in 7:59, what model is that ? Never seen such a thing like that before. Very interesting.

@michaelmeyers1827 2 жыл бұрын

I just watched a video you made on your 6mm creedmoore build. What stock did you put on it I have one I built and I put a krg stock on it it sure looks similar to what mine looks like

@richarddechau4200 Жыл бұрын

Thanks Gavin quick question, When you had Dave make your reamer did you request any special for the neck? I see you could install factory ammo, what did you request for neck clearance? I watched both cambering videos multiple times. Thanks Rick

@thetoelesszed 2 жыл бұрын

how can anyone thumbs down this video??

@sparkyferret550 4 жыл бұрын

Hi Gavin, great video, thank you, just a question, have you thought of spark eroding a collet to accept the barrel contour or are the jaws on you lathe independently driven so you can fine tune the grip on the barrel ?

@danbruce1899 4 жыл бұрын

Each jaw on the 4- jaw chuck can be independently adjusted.

@Jock856 4 жыл бұрын

Does the MPA Chassis accept those magazines as standard or did you have to do some modifications to make it fit?

@rgthomson100 3 жыл бұрын

i like your style nice job man, would have you do my 300 prc with confidence As for hanging in my smiths workshop no one gets in there when the lathe is turning lol

@jacobbowling6247 2 жыл бұрын

Machinist here. You can thread backwards (away from chuck) by putting your threading tool upside down, reverse your spindle and lead screw, (if they turn the same direction, right hand thread opposite directions left hand thread) 1. You don’t have to catch the half nut at just the right time, so you can use your carriage stop for positioning quickly. 2. You don’t have to cut a gutter (relief) in it 3. If you get into tool pressure issues, it will pop your threading tool up out of an aloris type holder before it damages your tool. This can be an issue if you’re using a screw on chuck that doesn’t have locking screws

@ThePigslayer Жыл бұрын

Coolest job in the world

@daleksr449 2 жыл бұрын

What chassie did you use on 300prc & what is the weight? I have bergara br 14 i love it but it's heavy

@SnipeU696 4 жыл бұрын

Thank you.

@Jace_DeGough 4 жыл бұрын

Dude, this is such a great video. I want to do this so bad. Keep up the great work!

@Ultimatereloader 4 жыл бұрын

Thank you! It's been so rewarding. I would encourage you to pursue the dream of building your own rifles. It's been one of the most rewarding experiences in my life! :)

@patrickbradford6223 3 жыл бұрын

What was the part number for the mitutoyo test indicator and extended tip?

@whitehedr 4 жыл бұрын

I really like the looks of that action. So much so that I am thinking of doing a 6.5 Grendel build around it. My range max distance is 300 yards. That is why I like the thought of 6.5 Grendel. At 300 yd the bullet will still be moving at a decent rate from the starting rate of the Grendel and from what I have been learning the 6.5 Grendel is not a barrel burner. The down side of going with 6.5 Grendel is the bolt face work required. I am not sure if I should start small and make it larger or start large and make it smaller. What are your thoughts on that? Also, is your action wrench modified to fit the Kelbly action? You mention the action as being a semi- clone. That’s why I ask.

@johngeddes7894 9 ай бұрын

The bolt face is what’s different. No recess on Kelbly.

@doinker50 4 жыл бұрын

Youre such a tease.. i thought something horrible was going to happen during that head space.

@christopherrobin9472 4 жыл бұрын

Yea I felt the same way!!!...Really took me for a loop!

@Ultimatereloader 4 жыл бұрын

Always pins and needles until things are checked!!!!!!! Seriously, heart rate elevated :)

@michaelohman4980 4 жыл бұрын

Heart in throat stuff, when I've done it! Same again first shot...

@Len_M. 4 жыл бұрын

Any chance I could send you a Sako TRG42 Stock and get you to make Comb Spacers?

@zzzzzzqu Жыл бұрын

The reason I'm asking is because I'm doing a savage receiver on a 300 PRC barrel and the place I got it said not to. Clamp the barrel But to clamp the action because I got a barrel nut what do you think?

@boober7270 4 жыл бұрын

So SICK!!!!! I hope you’re making 2 of everything. So I can buy one when you’re done. Great stuff can’t wait to see that baby shoot!!! 300 prc is going to be revolutionary in hunting in my opinion.

@p.t.anderson1593 4 жыл бұрын

I wonder just how deep someones pockets need to be to buy the finished rifle. Probably something along the lines of "If you have to ask... You won't be able to afford it."

@rocketsurgeon1746 4 жыл бұрын

Nice video. Maybe look into tenon relief cut. Many techniques but maybe rethink it a bit. Again, nice job

@randalljeffs7272 4 жыл бұрын

Just wow

@hantusmostert 4 жыл бұрын

Have you tried Inconel 625 as rifle barrel

@gregmcmurrey6640 4 жыл бұрын

Great video! I enjoy seeing your changes to refine the process. I have watched the DVD several times and will order the book now too. I do have a question if you don't mind sharing. Do you know the model of the turning tool you are using to turn down the tenon and to square the shoulder off? I feel like the tool I have has too round of a nose to square off the shoulder well. That looks like the right tool for that job.

@Ultimatereloader 4 жыл бұрын

Greg- that sounds like just what I did (watch DVD several times, then move on to Gordy's book :) ). The tool I'm using is a 5/8" indexable tool with DCMT insert (TiN coated) - tool is Accusize sdjcr10-3b from this set: amzn.to/34NV8ER

@gregmcmurrey6640 4 жыл бұрын

Thank you very much!!! I have the little brother to your lathe, the 13-40GT and have played and played and I am finally ready to do some barrel work. Thanks for saving me a few steps!

@Uberden 4 жыл бұрын

What is your trade or uni background mate? Or is it all self taught? Great shop set up and equipment. Fantastic location 👍🏼

@sniper13b 4 жыл бұрын

Gavin, Great Work. I have a Proof Research Carbon barreled 300 PRC built by GA precision. Maybe you could do the next barrel for me and we can do some shooting.

@svartblitz2511 2 жыл бұрын

LOGICAL AND METICULOUS. It's a pity that all these high-energy 30-s be it 300 RUM, 300 Norma, 300 PRC, 30 Nosler etc are soooo expensive and hard to come by.

@zzzzzzqu Жыл бұрын

Hey Gavin I went on rumble and could not find this video. My question? Is when. You were putting the barrel and check in? The headspace. How come you clamp the barrel? And not the action

@backwoodscliff317 2 жыл бұрын

This might be a stupid question but can you use a barrel with a larger OD then the actions OD ?

@mikemilgiore4917 Жыл бұрын

How would you have altered your disturbing for a carbon barrel?

@teo59 4 жыл бұрын

Don't you torque the action a certain amount? Do you do only with Hands?

@vrille66 Жыл бұрын

Hello collègue, at what rpm you use for reaming hss reamer ? Best

@jtmcfarland3512 2 жыл бұрын

I’m not a gunsmith, but would it be better to cut the inch off the muzzle end before clocking the tenon end of you’re looking for the final bore to be pointing up?

@123say 7 ай бұрын

About barrel which metal have used bro at video for this rifle tell me metal at video

@Potatogambit 4 жыл бұрын

I'd love to get into this stuff some day.

@Ultimatereloader 4 жыл бұрын

Do it!!!!

@Potatogambit 4 жыл бұрын

Need a lathe first. I have plenty of room in the shop for both a mill and lathe. Just gotta keep an eye out for a good older used one. I really appreciate your videos they are one of the main reasons I got into reloading. It helps now that ammo is a pain in the ass to buy in California.

@Ultimatereloader 4 жыл бұрын

@@Potatogambit Good deal! One thought- look for something with decent through-spindle capacity. The old Logans have 1 3/8" spindles (the 11" variety). Wouldn't be a bad way to go... I have a video on my old one if you look for it...

@Potatogambit 4 жыл бұрын

gavintoobe it will definitely be dual purpose. Again thanks for the advice. Guns,4x4s, along with living on a working ranch mean I'm sure I'll end up with something way more overkill than a need haha.

@Ultimatereloader 4 жыл бұрын

For the rifle work, you'll want something with extreme precision, for the larger parts (driveshaft work?) you'll want something BIG. Hard to do both on a budget. You may need two lathes!!!!

@kevinthree 4 жыл бұрын

When checking the headspace on a factory round remove the firing pin from the bolt. The action had no trigger and the firing pin will go forward as the bolt is closed.

@Ultimatereloader 4 жыл бұрын

Actually, there's a hole in the headspace gauge where the primer would be on a loaded cartridge, so no need :)

@markthegunplumber8376 4 жыл бұрын

saw that too. being a Gumsmith by trade i have a rule of no firing pins being in the bolt tube while working with live ammo. i have seen other gunsmithing shops with holes in the walls from using live ammo. in 24 years of business i have never had a ND and never want one, i also check all head spacing with the firing pin removed. it gives you a better feel without having a 22# spring hampering you.

@williamjohnson2896 4 жыл бұрын

Difference between GO and NOGO headspace gauges is from head to datum line, not overall length of the gauge. Overall may or may not give the true difference. I tried to find something quickly off SAAMI and came up empty for now, but , somewhere there has to be a datum line diameter and set of specs that is caliber specific for the difference. When you look at chamber drawings, I have JGS and PTG books reference is always from the datum line. Once the guage is made the user no longer has to be concerned with that "datum", useful in manufacturing the guage only. Keep it coming Gavin!

@Ultimatereloader 4 жыл бұрын

Yes, you are correct. Datum diameter for 300 PRC is 0.420" - so that's the gauge diameter you use for tools like Hornady's headspace comparator tool.