I have talked my brother into loading my 375's. Is crimping mandatory/suggested?? I'll (he'll) be loading swifts/TSX's/BAnded Solids all 300 gr.

Tips appreciated.

_Baxter

Crimp suggested. Due to recoil moving bullets into the case k

Thanks jeffeesso. Are there varying levels of crimp or is a crimp a crimp? Which die?

I've been loading for my 375 h&h for almost 20 yrs and I have never crimped my cases. I have a factory crimp die but never used it yet, I haven't had any problem's yet, maybe I'm just lucky. Measure the lenght on 4 rounds,number them with their lenghts, load them, shoot 3 and remeasure the last round to see if the lenght changed much, that should give you an idea to crimp or not. I use mainly hornady roundnose 270 and 300 grs with IMR 4350. Some Pistol, 45/70 and 458 lott are the only rounds I need to crimp. I have 4 other magnums that I don't crimp and they shoot great. You'll just have to try and see if you can get by with it. I also use rcbs dies???? might be part of it,don't know. You can adjust your die down to add the level of crimp you want or need or you could get a factory crimp die. good luck

quote:

I've been loading for my 375 h&h for almost 20 yrs and I have never crimped my cases

me2

I crimp my 375 H&H and 416 Rigby. If you're not using a dedicated crimp die, don't try to seat the bullet and crimp in a single operation. Do it in two separate operations. Seat the bullet without crimping then raise the seater plug and lower the die body to crimp separately.

The last week or so I've been do some load developement for a 378 Wby. Starting out with a slight crimp, the first one in the magazine is measured after two shots. I continue to increase the crimp until rear movement stops.
This was with a 300 gr TSX and 109 gr RL-22

Phil

I crimp 375 H&H Magnum loads but, from what others have said, it's probable that I don't need to. That said, I've found crimping in the appropriate groove on Barnes TSX bullets with a Lee Factory Crimp Die has given me very accurate loads so I'll continue to crimp.

roll crimp, taper crimp, and lee factory crimp .. crimping does make trim length critical, as you can buldge cases.. which is frequently why people don't like crimping, in some cases.

if i am just going to the range, i frequently don't crimp .. sighting in for hunting rounds? all bigbores and pistols get crimped

I don't find crimping my .375 H&H a useful practice.

I do a roll crimp for .375 H&H and now .375 Wby, I figure better safe than sorry since I hunt with them.

quote:

Originally posted by jeffeosso:
roll crimp, taper crimp, and lee factory crimp .. crimping does make trim length critical, as you can buldge cases.. which is frequently why people don't like crimping, in some cases.

A Lee Factory Crimp Die won't bulge the cases. Though for best consistency, case length is important, that die will crimp just fine even with a little variation in case length.

quote:

..... That said, I've found crimping in the appropriate groove on Barnes TSX bullets with a Lee Factory Crimp Die has given me very accurate loads so I'll continue to crimp.

I agree w/Grum. I use a Lee Factory Crimp Die w/300 gr. Hornady RN's & crimp in the cannelure.

I've also developed a few other cartridge loads using Barnes bullets where the LFCD crimped into the front groove has turned out to be a real accuracy enhancing measure, too.

Anyway, all the bullets you've mentioned above have a crimping groove in them - why not use it?

I crimp all my hunting cartridges with the lee factory crimp die. I've had bullet setback in rounds as small as the .257 roberts. I bought crimp dies for all my hunting rounds, it's cheap insurance.

I dod not crimp our 375/404 hunting amo.

I believe that if a uncrimped .375 moves, there wasn't enough neck tension in the first place. Haveing said that, I still crimp the solids.

quote:

Originally posted by Saeed:
I dod not crimp our 375/404 hunting amo.

Have you ever tested un-crimped rounds with crimped rounds? Using the crimp (light, medium, and heavy) to delay shot start?

I’ve always crimped so I have no data or idea.

No I haven't, not for this caliber anyway.

But, I remember us doing a test on crimped v uncrimped ammo a while back, using the Lee Crimp Die.

The crimped ammo did shoot slightly better.

In my own hunting ammo for the 375/404. My charge is slightly compressed, and the bullet are seated long enough to just fit into the magazine.

I am not sure whether these factors contribute to anything, but so far we have not had any problems with either the bullets being pushed back into the case, or jumping out.

And the load shoots very accurately in my two rifles.

Good enough for me to feel comfortable shooting at crocs brains at over 200 yards, and other animals past 500 yards.

quote:

Originally posted by Saeed:
No I haven't, not for this caliber anyway.

But, I remember us doing a test on crimped v uncrimped ammo a while back, using the Lee Crimp Die.

The crimped ammo did shoot slightly better.

In my own hunting ammo for the 375/404. My charge is slightly compressed, and the bullet are seated long enough to just fit into the magazine.

I am not sure whether these factors contribute to anything, but so far we have not had any problems with either the bullets being pushed back into the case, or jumping out.

And the load shoots very accurately in my two rifles.

Good enough for me to feel comfortable shooting at crocs brains at over 200 yards, and other animals past 500 yards.

Possibly aided by neck tension in the seating step? Since your dies are one-off customs, perhaps they have less slop in the neck area than a generic 375 HH die?

I don't crimp mine.

When I first got my 375, and set up to load ammo, I bought a set of RCBS dies. I had insufficient neck tension on the bullets with that die set, and you could pull the bullet back out of the case. About half the time, the bullet would pull out of the case when you lowered the cartridge in the seating stage.

I fixed it by going out and getting a set of Hornady dies. No neck tension issues, or bullet movement.

If I had continued to use that RCBS die set, I suppose I could have "fixed" it by crimping. I just didn't want to "fix it" that way.

I don't know if this is mandatory or not but all my 375 ammo is crimped with a Lee factory crimp die. I was told this was the right way to do a 375 and I have never had any problems. Is there a reason why you shouldn't crimp?