crimp or not to crimp

[shooter39629]

When I reload my encore in 444 marlin and 45/70 do I have to roll crimp the bullet into the case, if i am just going to shoot the rounds in a single shot rifle.

[versifier]

You have to try it both ways because only your barrels can answer your question. That is not unusual, either. Many straightwall cases need the crimp for uniform starting pressure, but often Contenders and Encores are a world unto themselves.

Sometimes a certain barrel shoots a crimped round better that you would normally load uncrimped, sometimes a different one prefers them uncrimped when you would be used to crimping them. My current "anomaly barrel" is a 10" .357mag. One would normally crimp any .357 round as a matter of course as it was designed as a revolver round. But, when I shoot 158gr swcgc's with heavy charges of BDOT to max length (way over what would be a safe powder charge or chamberable length in a revolver) if I do any more than just remove the bell from the neck, the groups open way up. With no crimp, they keep a nice tight cluster at 50yds - 1-2"/10shots. With light loads, it behaves like a revolver and wants a good crimp on everything. Years back I had a 10" .30-30 barrel that would not tolerate any kind of crimp - 2-3"/10shots@100yds vs. all over the paper. My current 21" Carbine barrel in .30-30 only likes crimped rounds and will keep its favorite cast loads easily in 2"/10shots@100yds and uncrimped two or three will not even hit the paper. My 10" .30carbine won't group anything that has a hint of crimp and is extremely picky bullet-wise even then. Neither .223 barrel that I have owned, 10" and 21", liked crimped loads. My .30 Herret 14" demands a crimp for cast and refuses one for jacketed bullets, which I discovered by accident when I forgot to run a box of jacketed loads through the FC die and the groups shrank by two inches. Live and learn.

I just try any new-to-me barrel both ways to see, and often now will check out every promising load both ways regardless of preferences that barrel has shown with other loads.

The one rule that so far seems to be true with them is that any light loads in straightwall cases have to have a good heavy crimp regardless of what the barrel might prefer with heavy loads, but just because I have not yet found an exception to this rule doesn't mean there isn't a ton of barrels out there that will thumb their collective noses (muzzles?) at me.

[kodiak1]

shooter I have 2 45-70 Sharps Rifles one shoots better with just a slight crimp the other one could care a less.

Ken.

[balzout]

Hello,

How much crimp are we talking about here? Is this one of the areas that have endless possibilities?

After I completed grouping my 30.378, I read an article that refered to the crimping vs. pressure that versifier mentioned. I was under the impression it had more to do with COAL stability in heavy recoil guns. During the grouping process I single shot my groups so I skipped the crimping thinking it might add some longevity to my brass. I don't feel I can go without the crimping in a hunting situation so I'm starting all over with 1/4 turn on the die. Does this sound like a starting point?

Thanks.

[versifier]

balzout,
We were only talking about loading for single shot Encores, Contenders, etc. If you are using a rifle that holds more than one round, I think that in general, more is better than less. For levers, I crimp .30-30's as much as possible without distorting the neck below the crimp line. I do not roll crimp anything anymore as I think factory crimps are more uniform, easier to adjust, and MUCH more forgiving when there is any variation in case length (i.e. I don't have to adjust the die constantly, just set it and forget it).

But, to answer your question, yes it is a good place to start. Run some through the action and measure OAL to see if there is any telescoping during the feeding process. If they have gotten shorter, more is needed. If all is GO, then load it up full, shoot one, and measure the other rounds, then load up and shoot two and measure. If they aren't getting any longer, you're where you need to be. If they are, crank it down a tad more.

[Tom W.]

I shoot Ruger #1 rifles and an Encore pistol and don't crimp my cartridges.. I do crimp for my revolvers...

[versifier]

Do you try them both ways to see if there is a difference in group size or POI?

[Tom W.]

Who, Me?

No, I get tiny groups as it is. Sometimes I leave things alone....

In my Encore pistol I get different POI with different brands of bullets. even if they are the same weight. That's not a surprise, however.

[deuceroadster32@earthlink]

My Winchesters doesn't seem to matter when I shoot singles, in the mag tube they need the crimp
The German AYDT Schuetzen rifle shoots well with no crimp!

Randy

[missionary5155]

Good morning I took my 44-40 Colt New Service out Friday am to try some 260 grain from a Rapine mold sized to cylinder throat diameter with 8 grains Unique. My 1915 made revolver likes a 205 grain "Bumped up" boolit from an origonal Winny mold with 9 grains Unique. I added my basic crimp to 5 rounds (folded over the front shoulder) of the 260 grain load. Fired two rounds and cylinder lock up.. those heavy boolits were creaping out like hungry wolverines. So next test will be with a much heavier crimp.