I have read that a more concentric spread of velocity is obtained by crimping all rifle bullets. But most Benchrest shooters don't do they? Seems like an important step like this in the reloading process would be universal if it had creedence. Granted, all of my big stuff is crimped for obvious reasons, but should it be applied to everything or is this just theory floated by people who know enough to be dangerous? Your thoughts on this are appreciated as I will some begin a rather involved loading process for several calibers. Thanks, Perforator
Posts: 399 | Location: Louisiana | Registered: 19 February 2004
Quote: I have read that a more concentric spread of velocity is obtained by crimping all rifle bullets. But most Benchrest shooters don't do they? Seems like an important step like this in the reloading process would be universal if it had creedence.
If you ain't shooting a benchrest rifle, what the benchrest shooters do or don't do has little relevance.
The only universal truth in handloading is that there ain't no universal truths. Each rifle is its own law. Only way to find out what works in a rifle is to try it.
I will say that crimping is one of the last things I try. It can help a lot when you are using a slow powder and have no other way to increase intial bullet pull. That's not the most common of situations, however.
Posts: 1570 | Location: Base of the Blue Ridge | Registered: 04 November 2002
Seems everyone has their own philosophy on this. I never crimp when I'm working up loads for a particular gun (unless as a last resort but that has happened only with my big revolvers so far and one 7 STW) but the last thing I do is test the best loads crimped because I crimp eveything I carry into the field. Clear as muddy water? It's an operational issue for me; I leave nothing to go wrong that I can think of when hunting. At the bench there's just not as much at stake.
Posts: 11142 | Location: Texas, USA | Registered: 22 September 2003
I was kind of thinking the same way. I have a couple of reloading friends who think crimping any caliber short of a .416 is sacrilege. I was working up loads for a 6.5x55 and decided to try a Lee factory crimp die on some of the loads. The crimped loads seemed to shoot tighter. I was not able to retreive the targets as it started to rain. I will redo this little experiment in the future.
Geronimo
Posts: 816 | Location: Michigan | Registered: 14 April 2004
As I understand the "theory". Crimping provides a more consistant starting pressure for bullet release. Also a more consistant ignition. The Bench Rest crowd dosn't do this due the fragile nature of the very thin necks (somewhere around .008"). They produce this effect by "jambing" the bullet into the lands.
If you go to the Accuratereloading home page, scroll down to the FAQS click on it. Then click on the "The Effects of crimping on accuracy and velocity" page. You will find that Saeed and friends did some experimenting with crimping and reported their results here. Some good reading. muck
Posts: 1052 | Location: Southern OHIO USA | Registered: 17 November 2001
I like to crimp .375's and up as well as .30-30's for a lever rifle. The Lee crimp die is a much neater solution than crimping using the seating die, since small variations in length of the case will cause variations in the crimp. I can't imagine this will increase accuracy. I use a crimp when I feel I need to be sure to hold the bullet in place due to recoil. Lee doesn't catalog a crimp die for the .416 Rigby (they will custom make one) so while I was waiting to get one I did without a crimp, worked fine, so who knows?
Posts: 2788 | Location: gallatin, mo usa | Registered: 10 March 2001
I Never crimp my rifle bullets if they are for a bolt action or single action. Most of the time its one round at a time for me. But for my AR-15 and SKS I always Crimp.
Posts: 83 | Location: Lapeer, MI | Registered: 19 February 2004
I like to crimp everything with the Lee Factory Crimp Die, for the reasons that have been stated. In my experience there's usually a small gain in accuracy, velocity consistency, and average velocity. I'm not seating bullets right against the start of the lands or into the rifling, as the benchrest shooters do.
Posts: 1325 | Location: Bristol, Tennessee, USA | Registered: 24 December 2003
I only crimp big bores that may set a bullet back in the case with recoil, if the bullet is left too many firings in the magazine...
If you want consistency then turn about .003 off the resizer button and use a powder that nearly fills the case is a better solution providing your dealing with a chamber cast of your rifles chamber IMO...
Posts: 42210 | Location: Twin Falls, Idaho | Registered: 04 June 2000
I just finished an 80 round test in one of my rifles (700 Varmint 308) to check out this theory, and at least with my accuracy loads, the crimped rounds were more accurate in every case but one. So it looks like this rifle, with IMI brass and Sierra 168 gr MK's and Win LR Mag primers and this lot of surplus powder, prefers a crimp. How's that for definative? - Dan
Posts: 5285 | Location: Alberta | Registered: 05 October 2001
In 223 I have had good results both ways. Lee FCD, and uncrimped.
The loads that work well one way are not the same as the loads that work the other. In other words the loads worked up with a crimp worked fine, the loads worked up without a crimp worked fine too. But the loads were not exactly the same. I did not directly compare any single load with/without crimp to get data. " worked fine " is a relative term meaning that they seemed to group normally for the gun they were shot out of. My AR is usually about an inch for 20 rounds at 100 yards.
