I love these tests you do. I've learned a lot from watching your channel and it's saved me a lot of time and money. Thanks for what you do.

6 years old video but still relevant!

I've been reloading for some time. Yet, im new to auto rifle. This was great information. Thanks for taking the time to do this and sharing with us. Good job!

I really expected to see more deviation from NO crimp to the extreme X-Heavy crimp. Even the pressures didn't pick up as much as I thought they would have. Excellent video buddy.

Great test and content. Very helpful to someone getting into reloading. Thanks for doing this channel.

Literally love nerding out on these vids, good job

This video is very well done! Not overly talky. Great target and shooting visuals. Thanks!

Proper cannelure dimensions are required for the 5.56 roll crimp to work effectively. "Ghost Crimp" first offered by Sierra was rejected in favor of the Nosler 77 gr OTM cannelure on the Black Hills Mark 262 Mod 1, until Sierra came around to making a fully developed cannelure. You can see the waffle impression on the soft case mouth from the bullet cannelure on fired federal XM193 military cases. I think the extra grip between bullet and case used by the military was for added insurance against poor neck tension and subsequent loose bullet from jamming the weapon.

What a cool test! Putting theory to paper to quell the masses!! DAMN I love this channel!

Great video! These videos are very detailed and well thought out. Tons of serious information to be gleaned here. Keep up the awesome work!

Thank you for this video! You answered that question I always had in the back of my mind in regards to crimping. I will continue with a light crimp on my 223 reloads without any more doubt about going heavier!!

Just started reloading and your videos are the best I could find!! You don't talk too fast and you dont talk to slow. Your precise and concise. Keep making them

Lol. That is my favorite website for supporting all my favorite content creators!

Well done Johnny, here is my two cents worth. For years I crimped my 223Rem/.556 ammo with a medium to heavy crimp for the simple reason of bullet push back, in competition causing jams. In the last few years mostly bench shooting on my part and never crimp, and no issues so far.My only comment with the bullet you are using why OAL 2.215", my preference for that bullet OAL 2.247".

Best link at the end of a video yet, well played

I do a mild crimp on all my 223, after some rounds jammed in my Armalite and it was because the bullet had been pushed back on the feed ramps.

I crimp just enough to prevent bullet movement under recoil and cycling.

You are a god to the new reloaded And new to to bobs bullets. Thank you

The heavier the crimp, the higher the POI shift is what your test seems to show. I have a hornet, and I was instructed to always put a light to medium-light crimp as they have low neck tension. Thanks for the test, bro!

Glad you went back to LC brass. They take pains to assure a soft annealed shoulder and neck. This serves to make sure the neck seals to the chamber during firing. The downside is that if you get too heavy on the roll crimp on your press, the shoulder will flare where it attaches to the shank of the case. It can be subtle and go undetected under visual inspection. It can even sneak through the Wilson Pattern Gage Test. When setting up for a roll crimp into the cannelure keep an eye on possible shoulder flare. By the way the MilSpec for M193 is 35 lbs neck retention. The Military does not insist on crimp but LC throws it in to assure there are no disassembling or bullets pushed back down in the case during the autoload forces and the 35 lb. minimum milspec requirement is maintained.

Love the “I can feel it all the way down to my plums”🤠

Glad you did this. I had an old timer tell me he never crimps 223. He shoots competition. Hence I dont crimp

Well Done Sir! A real life, this is what I did and here are the results test. Thank You!

I've crimped mine with a light crimp because it came with my kit. Interesting results.

Your video's are the best, in my opinion I've learned so much and have watched for hours thank you 🤠

I've been reloading for over 30 years and never bothered crimping. I was just gonna start playing with crimps and found your video. I prob won't now. Great seeing this... I would think just to put a little more tension on the bullet.

I know I am about a year late for my comment but I only found your channel in the last week. So u can probably expect a few late comments on other videos as well as I watch them. :-) great content! loving the channel and experiments

Really enjoy your videos lots of great content!

The video clips thrown in make me laugh every time. The 8541 tactical made me laugh out loud at work when I shouldn't have been watching videos. I've never crimped, haven't had a reason to, and I get good results without it. So it saves me another step I guess

No crimp pimp. LOL I just wanted to thank you for your hard work and sharing with us brain stems out here.

Many moons ago I performed a variation of the test you did here. I used cases sorted by stamp, 55 gr hornady FMJ bullets, and two different ball powders (H335 & TAC). I tested medium crimp vs no crimp at various charges weights. I had similar results. Sometimes the crimp yielded better consistency, and sometimes not. Data was so inconclusive that I also determined crimp doesn't make much difference with plinking ammo in an AR platform rifle. However, for my target rifle I'll often achieve a spread under 15fps. I never crimp these rounds.

Awsome video bud,thanks for sharing 🎉🎉

You certainly go after the questions I have.

I have read in multiple forums about reloading .223 and a lot of reloaders do not crimp. Good video, Thanks!

I have found that crimping tends to elongate the bullet by .001 to .002" so that may explain the extra thou in your measurements.

Need to run the crimp test with multiple powders. That might provide more decisive insight. Great work, too!

Whether you apply a crimp or not, I have found uniformity in neck tension is the criteria that's important.

CRIMP: Just enough to get it done.

I think the changes in group sizes are due to the barrel heating as the first through third grow progressively bigger until you take a break then the same thing happens again

great video btw i love the content keep it up!

The best way to describe crimp is to hold bullets in place in auto firing guns. And some powders do better when bullets are crimped to 🔥 all the powder up. The old wise tail says if you can't push the bullet in with pressing it against something your fine and just lightly crimp them to iron out the lip of case.

Awesome link at the end Johnny lol

Thanks for the video, tell me one thing, currently what do you use? No, light, medium or heavy? It was weighed not to use, that in the caliber 38 special, what do you recommend

Great job man! So the question is: to crimp or not to crimp. I personally don’t crimp my bullets, even if I do “fire-fire” with my AR15, or bench rest with my 308 Remington 700. The reason is that I prefer to not stress overall the neck of my cartdriges, since I reload them. This is my opinion. Anyway, thanks for making this video, and sorry for my english. Greetings from an italian guy :)

Interesting video, always good info Bro. Thanks for sharing

Thank you, for confirming why i don't crimp for 223. No real accuracy gain as well as velocity jump. I use a .002" neck tension and it seems to work well.

Thanks for the video man. Well put together. If crimping doesn't change SD or grouping much I could see a hunting vs bench application for crimping. iE if your walking through the shit and your bullets are josling around In the mag or your pocket etc.

I was taught to always crimp compressed loads and anything that will be stored for any length of time. I.e hunting loads. Other than that, it's shooters choice. What do the manuals say?

I've been loading 300 HAM'R (basically 223 brass cut and necked up to 308) and had to crimp (mid to light) to keep the bullet from pulling out of the case when chambered. The inertia from the 125 gr. bullet made it push out into the lands. If I pulled the bolt back to make sure the round loaded from the mag it would pull the bullet the rest of the way out; turned into a powdery mess.

I would try them without the can on the end- it with the sensor on the end may be affecting the barrel flexing.

I’ve never used my factory crimp die on 556. Just a normal neck tension on the lee seating die. It takes about five whacks with a kinetic bullet puller to knock a bullet loose. That’s plenty tight. As an aside, 25.5g H335 is above the new max but below the old max and gives great groups (Hornady 55g fmjbt, CCI 400 primer, 2.215 COL).

Very interesting and well done. I crimp the .243 rem I own, It is a Tikka T3 varmit. I find crimping improves the rifle's performance, I use it mainly for pest control on Fox, Kangaroo, and Fallow Deer (NSW, Australia). I would say I use a heavy crimp, but I think I will go back and look over it again as you have now got me thinking, I could improve.

Thank you! Very informative and well done video. I’m just starting rifle reloading. If the bullet has a cannelure, is the crimp is still optional?

Good stuff. I did a similar .223 test a few years ago. Unfortunately, it was before I had access to a chronograph. My groups looked like yours. Not a lot of deviation. I expected variations. It surprises me to see no bullet creep or major change in velocities. I wonder what this test would look like with a heavier caliber?

From what I understand, crimping bullets came about after most of the worlds armies learned that soldiers during battle can be very hard on their ammunition. Using bullet tips as tools, running through red hot machine guns, slamming home bolts, double feeds, etc. Crimping also came about due to war time production as neck tension could sometimes vary quiet substantially. Crimping was just another step to decrease the likelyhood of a misfire damaging the weapon. Today, the quality of modern brass is just out the freakin roof, even with cheap brass. Crimping can help, but is not needed. I think all of us, early on in our shooting career, "heard about that one shooter" who had a round pushed into the case and blew his face off. So we intuitively added crimp, JUST IN CASE. lol

any sign on the new video? the things you are going over are exactly whats going through my head at the moment. i think ive found the right load weight for my powder but now its just getting the crimps right (which judging by your video im doing a "medium crimp") and now looking at my bullet lengths to see if i can tighten my groups. i had shot 2.900" COAL for my 150gr HPBT sierra #2190 .308 which was an excellent group, but the bolt was very tight, so i went back to book standard and reduced it to 2.750. i've now increased it again to 2.775 to see where we are with it, still within the books spec but at its max length - after that it will be my own world. takes serious money to do this in the UK lol

I would like to see this with Vihta Vouri powder. That powder has given you the most consistent low SD #'s.

How long do you let the barrel cool between groups?

I believe crimp matters more with heavier/longer bullets. really noticed this with the 300blk subs bullets moving forward when cambering.(dies maybe?) Never had any issues with 5.56/223 bullets i've loaded, but I crimp them anyway cause of bullets getting shoved in cases in ammo I didn't load. The SMK 69gr are the heaviest i've loaded.

I just crimp enough to rid my reloads of the slight case mouth flare, that I use during reloading. To smooth feeding. Light to extra light crimp.

Johhny's Guessing Bench

I shoot a Howa .22-250. My favorite load is 52gr. Hornady match, CCI BR2, Hornady brass, no crimp OAL 2.370" case trimmed to 1.905. I finally got a 5 shot group under a dime at 100 yards. (Forget about the other 300 groups under a blanket).

Where do you reload at? Shed, garage or inside the house? I don't have a shed or garage. Just curious on your opinion.

I love science and I love testing that makes sense. 50 shots isn't enough to "prove" any theory but the way you conducted it proves to me that crimp just doesn't matter for 223 or 5.56 range shooting. All reloaders are crazy but we really appreciate a good video like this one.

Sir, the group with no crimps...did you just used the Lee's bullet seating die? If so, it cycled all the way through ,you took the last round out correct?

Crimp isn't about keeping the bullet in the same place on a standard feed, or really for accuracy, or for SD/speed. If you size you case properly the standard neck tension will hold the bullet, even one without a cannulure, in standard feed semiauto. What a crimp is for is a safety factor when you have a jam. A proper crimp gives you confidence to ensure the round is still shootable when you have a jam. I could have told you the results of this test before you did it... it would change nothing you were measuring.

I'm a advanced reloader of over 43 years , advanced ultra reduced center ammunition. all my semi auto ammunition I prove each round with no exceptions. I cross both thumbs around prime end, bullet nose betweeny fingers and push hard against a board on a table, reloading bench,door frame of reloading room. having my micre meter set to check for bullet back up .I don't buy much factory ammunition but I'm shocked at how easy to back in case some brands are also extremely dangerous ammunition.lets face facts most shooters get out shoot she spray and pray method and because you just can't see while rapid firing bullets backing up in cases then blowing up. I'm 99 percent convinced most semi auto firearm failures are due to faulty ammunition.its a experience I won't never forget. papa.

Much more important is to get the thickness of the neck brass even around the circumference. There will always be thicker and thinner spots. This means that your bullet is not in proper alignment with the barrel bore. Only turn it to take off the high spots, so you’ll typically only get cut marks 3/4ths of the way around. And as always, neck tension should be .002” less than actual bullet diameter compensating for neck brass thickness. No separate crimp required. Now this is for your match ammo that you baby, not the stuff for blasting with the fellas.

Wow . Great vid !

In my opinion crimping for rifles is more based on how you are going to use the gun. If its a self-defense or gun fighting battle rifle setup, you want to crimp. The rifle is going to be dropped banged around on things, etc and you don't want the bullets shifting. If all you are doing is bench shooting, then who cares.

have you ever found a good ES and SD using 55gr bullets like Hornady BTSP with H335? Im having the same problem it appears you had here.

What bipod mount is that?

Just bought a 1000 BB (bobs bullets) and cant wait to load them up!

Was wondering your thoughts on 30/30 crimps

Hello Johnny! Long time no see. I came back to just get some action waiting on your next video. I noticed that with the heavy crimp, the ejection pattern was more consistent, and the group was tighter. Just an observation and a chance to say what's up!!?

Johnny you da Man!!!!!

I started crimping .223 because the crimp came with set! But something strange happened when I was trying to develop a new load. When I test chambered a round, the bullet got jammed WAY down into the case. Scary! In your opinion, could crimping prevent that from happening?

The cannelure on those bullets is what we call a pseudo-cannelure, invented by Sierra when Mil asked for a real cannelure on the Mk262 Mod 1. According to Dr. Corbin, a real cannelure will establish a line terminus of the cannelure indent if it is to be functional as intended.

The only round i've every found to benefit from a mild crimp was the .22 Hornet. Other than that i just size the case neck, (Until it needs a full resize. Bolt action.) I just always seat bullets at least as deep as the width of the the caliber and around 5 to 10 thou from the lands. Best group i've had at 100 yards is .25" give a thou or 2. That was a dead calm day though, and i happened to be on form for once!

Wondering about the Chronograph you are using. Do you notice any trouble sighting in your rifle with it being on the barrel? The slightest deviation on my barrel and shot placement is all over the place.

I load those bullets with AR COMP with lc brass with 25.7grains and use winchester small piatol primers And get very very small groups at 100 yards COAL is 2.245 No crimp in a 1 in 9 twist 16 inch barrel Works great in my friends ars as well No small rifle orimers so we made do with the small pistol primers Whats your thoughts about this load

So glad to see a vid without hornady bullets

I personally, would be happy with any of these groups.

Single feed from a shooting bench? none. In the field hunting? Enough to prevent bullet movement while in the magazine.

Enjoyable and interesting.

Have you had the crimp die deform a shoulder/roll it a little? Have a RCBS crimp/seating die and that's what it's been doing. Put a factory round in the shell holder lift the ram all the way up and then screw the die in so I have seating depth and crimp. After this a put a round in to seat and crimp and comes out with a rolled shoulder.

I generally use a crimp only with plinking ammunition that has a cannelure. While there are sometimes accuracy and pressure differences... I don’t see enough to worry about. I use a crimp in bulk stuff just because it gets thrown in an ammo can and carried around. I find best accuracy and SD’s out of controlling neck tension and seating depth. I seat to 2.25 to 2.26 depending on the round. For me the golden number has been 0.003 of neck tension. I use this in all my rifles. I recently used a very light crimp on 300 blackout but have yet to fire a single round to test. You should really try the 77 grain Berger tactical with Varget... I’m curious to see your result. H335 I like with 55 grain... I prefer a little slower with powder with heavier. Varget, 4166, CFE, etc. when you clean don’t remove too much copper, accuracy will fall. If it’s a new barrel it could need broken in more as well. As far as your take on crimp needed or not... I don’t see the real need unless storing like I mentioned. Good neck tension is what’s more important... keep the awesome videos coming. I would say where it is relevant, in pistol, especially in magnum revolver cartridges. In rifle I crimp only 223 and 300 and for storage. High accuracy stuff even in 223 gets no crimp for me and I get beat SD and velocity with neck tension. Crimping can actually reduce velocities when you need it due to more energy blowing expensed to make the bullet leave the case. A longer COAL will get you higher velocities with good neck tension... that’s a little bit of a ramble and I’m sorry. Just got up with minimal coffee in the system lol.

I always thought it would make more difference than you got there. But then you rarely ever see factory loads in any caliber that isn't crimped, some of it crimped pretty hard. I really would have bet it raised bullet pull a lot having to break the crimp back out before the bullet could move. Guess not.

My view is that I use a light crimp when the bullets have a cannelure. On longer bullets(55gr Nosler BT) with no cannelure, the bullet is seated deep in the case and does not need a crimp. I just don't think the crimp adds anything. YMMV

Nice fotos. Really obvious how the bullets form a waist with crimping and thereby loose contact surface with the barrel.

This puts another wrinkle in my noodle. I started reloading 30-06 and 460 S&W mag, guess crimp has been engrained in me. Only load I really don't crimp is 300BO , since I just am removing the bell. Going to try no crimp on my 5.56 now.

crimped my first time today... a bit nervous. .. my case lengths weren't consistent and I screwed the die in further so it would hit the brass most are right on the edge of the neck a couple are .02 lower should that be okay?

can you do this same test with a known good load for 308?

What was the purpose of measuring the last of each group w/ the calipers??? Was it expected to change length in the clip?

As I understand it you should not shoot for groups with the magneto speed chrono attached?

Hello. I have a question that I am hoping you may be able to help me with. I have been reloading 38 special for some time and have always used bullets with a cantullure and I would crimp my case mouth into the cantullure. I recently purchased some berrys bullets without cantullure, will i still be able to crimp the case mouth or not because there is no cantullure. Please help. Chris

Is them boat tail? Other than creating a round crimp groove, fcd does not distort any bullet. Lee said so and I have seen it’s true. If you can feel the edge of the case with a drag finger test, it’s not crimped. Send it back to Lee with a case and they will make it right

Crimps are military standard. As with cci # 41 primers. I use a lee factory crimp die on all simiauto reloads. Very lite to lite. Military uses a heavy crimp standard do to the handeling of munitions and to insure proper feeding in combat as well as training. With combat they are looking at combat accuracy not bench rest. To test standards you must measure crimps on factory loadings with digital just as you would for proper pistol munitions. If your banging out more than ten in the mag such as the 30 round standards everybody uses today, I use ten, then you could see a little backwards movement by the time you reach the last few. How fast you jackhammer them out can also have affect. Clean barrel with a snake between strings to set a standard. That's my way when looking for accuracy load. But every body has there own way. Just like opinions and But holes everybody has one.lol. fun fun fun.

Your video is excellent! The test hypothesis is excellent! You are testing more than just the crimp! Please excuse my next question. I do not intend on being rude. I am simply looking for extreme accuracy. The shooter is part of it. Have you ever entered any competition shooting? Have you ever taken shooting lessons? Also How was the wind that day? Thanks for what you do great job!!!!!!! Ok here are some thoughts. Effects on SD can be broken down into groups. Horizontal deviation and vertical deviation Horizontal deviation caused by things that move the bullet left or right. *Trigger pull, *wind, *rifle hold, *rifle riding the rests, rifle bedding, bullet and case concentricity, *fouling, *temperature change, barrel mfr Vertical deviation- caused by things that move the bullet up or down. *Load variations, CRIMP! , *heat, *temperature change, bedding, rifle riding rests, fouling, Bullet and case concentricity. Rain, barrel mfr * = major contributor JUST FOR AMUSEMENT IF WE SAID THE HORIZONTAL DEVIATION OR THE HORIZONTAL SPREAD WAS DUE TO THE SHOOTER AND WE CHOSE TO LOOK AT ONLY THE VERTICAL DEVIATION OR THE VERTICAL SPREAD As the vertical spread is where we would expect to see the change in group spread caused by crimp. WHAT Do THE GROUPS TELL US THEN??? NO CRIMP. You first group the control group was 1.29 in vertical spread. LIGHT CRIMP 1.49 - 1.29 = 0.20 increase vertical spread MEDIUM CRIMP 2.10 - 1.29 = 0,79 increase vertical spread HEAVY CRIMP 1.50 -1.29 = 0.31 increase in vertical spread X-HEAVY CRIMP 1.30 - 1.20 =. 0.01 Increase in verticals spread THEREFORE THE STATISTICAL DATA TELLS US ALL FORMS OF CRIMP INCREASED VERTICAL DEVIATION IS THE STATISTICAL DATA COMPARABLE TO WHAT YOU SEE IN THE REAL WORLD? Yes (maybe). I have never seen any benchrest competition shooters CRIMP their cases. It is said that crimping cases decreases accuracy a small amount. (BENCHREST SHOOTERS ARE SUPREMELY CONCERNED WITH THE SMALL AMOUNT OF ACCURACY). THE DIFFERENCE IN COHESIVE FORCES IN THE BRASS METAL CAUSE VARIATIONS IN THE RELEASE OF THE BULLET CAUSING MINOR CHANGES IN VELOCITY RESULTING IN MINOR CHANGES POI. . CRIMPING THE BULLET IN THE CASE IS USED IN THE MILITARY TO PREVENT CATASTROPHIC FAILURE. TO PREVENT MOISTURE INTRUSION INTO THE POWDER AND PROBLEMS CAUSED BY THE BULLET MOVING IN THE MAGAZINE DURING AUTO FIRE WHICH CAUSES FAILURE TO FEED JAMS. THE MILITARY IS WILLING TO SACRIFICE MINUSCULE ACCURACY LOSS FOR GREATER RELIABILITY. To some degree your test bears out what one would expect to see. OR I.Am nutz

Good video the thing is there are so many variations to reloading and testing. I feel the biggest is the gun and the shooter. The only way I see for the best test would be that the firearm is clamped down and it has the same Barrel condition every time from one load to the other. Just my two cents