I am trying out some Hornady .224 75 gr MATCH BTHP bullets for use in my BCM M16 upper. I have a Lee FCD but do not know if it is necessary to crimp or is the neck tension enough for an autoloader with non cannelured bullets? I full length resize with a Redding 223 Rem FL die. I’ve heard from some that a very light crimp is recommended and from others that no crimp is necessary at all. So what say you?
Also if I were to crimp, how will this affect the amount of powder used due to the slightly increased pressures? Hornady’s page on the 75 gr BTHP cites a max load of 24.1 gr RL-15 with the load prior to that as 23.3 gr RL-15.
I would put a crimp on it. A taper crimp just pushes the neck up tight against the bullet and will work without a cannelure. I have some non-cannelure 75gr BTHP from PRVI and have not loaded them yet but will be doing this on them
See the recent Kaboom thread that appears to have happened due to setback… I’d rather be safe than sorry and so I do my best to make things as safe as can be.
I’d rather be safe than sorry. I don’t think that this sort of crimp should affect pressure in any meaningful way but that is just a guess. Check for signs of pressure etc etc etc like you would when working up a load.
I have not used the Lee FCD but it should crimp (its in the name). I would assume you just screw it down to increase the crimp. Does it contain instructions?
I have a few around here on the shelf somewhere but have never used one myself (yet).
Yeah directions just say to screw it down little at a time to experiment with crimp. What I really meant was how much of a crimp is necessary? I’d rather not be damaging the bullet with a crimp. I wonder if Molon has a write up on this…
You’re not damaging the bullet anymore with a crimp than a similar bullet, which has a factory cannelure applied, is damaged.
The Lee FCD doesn’t apply a taper crimp, it applies a unique style crimp that is even all the way around the bullet from the top of the crimp to the bottom of the crimp (a taper crimp crimp crimps harder at the top than the bottom). I recommend you experiment with crimp pressure, but in my experience you don’t need much. Start out with half the pressure that Lee suggests in their directions and adjust die in small increments and test for accuracy. If you can get above your press and look down into the die you can see the collet squeeze the bullet and apply the crimp. You can get a sense when you’re starting to apply a crimp and when you’ve gone overboard.
I have mine adjusted to apply the light-moderate crimp. It’s enough to guard against bullet setback but not so much to do major harm to the bullet. IIRC, crimp pressure is slightly less than what Lee includes in their directions, but honestly, it’s been a couple of years since I set it so I could be off a bit in my recollection. I know that I can’t get a seated & crimped bullet to budge by pressing a loaded round into my bench, bullet down, with many lbs of pressure pushing aginst it. But this has as much to do with ensuring proper neck tension exists, and that’s a function of having your resizer set up properly. This equates to polishing your expander ball down or using the correct bushing. Crimp pressure is not a suitable workaround for inadequate neck tension, and I polished my expander ball down to ensure about .003" difference between resized and loaded rounds.
I tried working up some tonight. I do not have the hornady manual to see exact load data for the 75 gr bthp. So I used the sierra 77 gr mk data of a min charge of 22.3 gr rl-15 and just tried 22.4 gr and had an accuracy of +.2 gr from the goal of 22.4 with most being exact 22.4 gr. I think I have just been spoiled by the scales I use in college for chemistry. The hornady powder dispenser on the lnl AP is about as precise as it’s going to get. All brass were trimmed to 1.750". Coal varied up to 0.003" below 2.260".
With the lee fcd I set to lee’s instructions and ended up backing off a smidgen. The petals of the crimped would collapse down just a slight amount on the neck. I tried forcing the bullet into the case witb a good amount of muscle and it would not budge. Success so far until I test them. I made some with crimp and some without. Although because of inconsistencies of the powder, brass quality, bullet mass, and etc. Just now to buy a chronograpgh.
If you’re concerned about it, buy military ammo. The bullets will be crimped into a cannelure and the bullets will be “Glued” or asphalted into the neck.
If you’re shooting for accuracy you’ll be loading with proper neck tension – usually with a carbide size die (like a Redding S-die) specifically for your weapons, sizing the case neck 2 to 3 thousandths of an inch smaller than bullet diameter.
Reloaders using standard full-length sizing dies with no consideration for bullet diameter, with large buttons on their decapping rods, shooting in chambers on the fat side of SAAMI or MILSPEC / NATO risk bullet set-back. Setback bullets may raise your chamber pressures to unsafe levels.
Crimping a match bullet with either an excessive taper, without a cannelure, or with a Lee Factory Crimp Die risks separating the lead core from the copper jacket, making a bullet that wobbles about its axis. Unnoticeable from muzzle to 200 Meters (where most folks shoot) but will definitely be apparent at longer ranges (especially if trying to take precision shots with magnification).
Buy good reloading books, get the proper tools, and load with the proper dies and components and you’ll never have to worry.
Go around blind and you’re always guessing and worrying. 99% of the M4/M16/AR shooting crowd will never notice the difference.
Thanks for your insight, sinister. I found the coal was too long at 2.260 for magazine length and set them back to 2.250" with an observed 0.003" variation. I’m guessing it has to due with slightly non uniform meltplats on the loose packed Hornady 75 gr bthp or likely due to my seater die not being comp’ grade per say(standard 223 2 die FL redding).
With a new batch I tried 2.250" coal with all cases at 1.750" oal ±0.001". 22.8 gr R-15 with ±0.3 gr observed variation from the powder drop. Seating die was turned out a full turn to avoid the integrated crimp on the redding seaters. I set the Lee fcd to a very light crimp(looked like it was just doing a little more than an all around touch) and checked the strenght of it by putting some marker on the neck and saw light marring of the color. Primer pockets were just cleaned with a brush.
Now about neck tension; is a special tool required or can I use standard calipers? Right now I’m mostly just interested 0-200m target and small-medium game hunting. That and I don’t expect too much better than slightly sub moa from this upper. Good enough for small whitetail and feral hogs around here though. I’ll invest in a single stage, a better scale, and some competition dies for longer range work once I have rifles more accurate than my K31s.
I’ll try getting to the range to try these out scoped at 100 m. Any recommendations for a good chronograph?
If your sizing die is working correctly you do not need to crimp any bullets in the 223/5.56. Load the round, put the bullet on a piece of wood and put some force on it, a bunch, like use some ass on it. If it moves, you need to get a sizing die that sizes the case more or mic your bullets.
If you are having double feeds and cartridge stoppages that are pushing bullets into the cases you have other problems and crimping bullets is not the solution.
BTW, the one set of dies that I used that would not size the case enough to hold the bullets was made by “Lee Precision”. Those two words should never be used together. Lee’s stuff is junk and you need to be told.
I use Lee FCD on my AR handloads with good success on Hornady and Nosler OTM’s without a cannelure. I’ve stripped no jackets and I put a pretty heavy crimp on the rounds. The ride from the mag to the chamber is not a gentle one and I see it as insurance. I have been unable to drive any bullets deeper in the case with considerable force. I load very warm rounds as well.
I see a little variation in the COL using OTM’s in 223 and 308 measuring with calipers.
I used to use only RCBS dies, but after several stuck cases and broken deprimer pins and other fustrations am worming my way out of them. I have used Lee dies since they first came out with NO issue over all these years. If I happened to hit a hard/berdan primer the Lee die would push up the decaping pin. I would tap the pin down and tighten the decapper. Simple, no cost, and it works great. I used to shoot long range matches, at Fort Benning, and have NEVER had an accuracy issue with the Lee dies or the the tapered crimp die. That was both 5.56 and 7.62x51.
I have friends shooting the, 6.5 Grendel, who get sub MOA all the way to 1,000 yards with NO issues. They too use Lee dies. :D:D:D
All hollow point bullets will show length variation unless you uniform trim the meplats (really more work than it’s worth since you’re using a +/- .3 grain powder variation rather than trickling charges).
Factory dies should be OK if the farthest you’re shooting is 100-200 yards and you’re shooting woodchucks to deer.
Measure your bullet diameter with your calipers; select a die that will neck size your case mouth opening to .002 to .003 smaller than bullet diameter (your brass will squeeze down, but will also spring back out about a thousandth due to the elasticity of brass).
Any crimp defeats the purpose of an accuracy load for extended ranges. My guess is you won’t be able to discern much difference at 100-200 yards. The proof will usually show at 300 and out.
There are gages to check force required to seat, but your best gage will be your hand (you should be able to feel the difference between bullets that seat harder or softer than the mean).
A precision/match shooter is going for consistent, small 10-shot groups centered about an aiming point (the X-ring or center-of-mass of any exposed part of a hostile target). An occasional hiccup won’t bother a guy shooting at groundhogs or coyotes, but it can lose a precision shooter a match or a firefight – with other consequences.
If you’re going for big money or bragging points (i.e., benchrest or turkey shoots for prizes) nobody crimps. Crimping is to minimize the possibility of mis-feeds with added pressure and safety risks.
Your 22.8 charge seems a little light, but I will err on the side of accuracy and consistency over velocity. The Lyman manuals usually reflect slightly higher charges than both Hornady and Sierra.
A BCM is a good barrel and MOA to slightly better is very do-able. Try to minimize your variables.