Lee Factory Crimp

[JP]

Sorry, but I have another novice reloader question;
I have started reloading and with some success so far. I mainly use the lee equipment and have the lee "factory" crimp. Among lees abundant literature he recommends it for all types of rounds etc.

The heads seem well seated when I reload and I have not used the factory crimp yet, so does anyone have any views on whether it is advantagous to crimp tighter with the lee factory crimp or not?

I can see/have read the physics of why a tighter crimp would work better, but does this relate to reality and if not crimped is there really any danger of the head moving when out hunting (normal due care taken)?
Cheers
JP

 

[Muir]

JP: The chief benefit from crimping rifle ammunition is not to prevent movement of the bullet during recoil, It's to make pull weight uniform. In other words, to make the amount of pressure needed to break the case neck loose from the bullet, uniform. Crimping is a good way to insure that.

Yes, case neck pressure alone can work but crimping helps to negate any variances in neck thickness or resiliency. Both of which can effect pressures.

The Lee Factory Crimp die is a good item. I use it on most of the different cartridges I load for. In some loads I have seen no award-winning improvement in accuracy, but in others -most notably the .22 Hornet, a cartridge with very inconsistent brass thickness- I have seen dramatic reduction in group size and standard deviation of velocity.

Give it a try. ~Muir

 

[Thar]

I have tried crimping bullets in place and then tested them against cases with uncrimped bullets. I could detect no adverse effect on accuracy, this may be because I use quality brass:- Norma or Lapua, so the neck tension is consistence. If for no other reason than it makes my ammunition more robust, which in some of the environments which we stalk in is no bad thing I tend the crimp my stalking ammo.

ATB

Tahr

 

[JP]

Muir/Thar

Thanks for the advice I will carry on and start crimping for both the reasons you give. Much appreciated.

Results are good so far without crimping and nearly half the group size of my best factory ammo! in fact most shots overlapping clover leaf style with the first two batches of five rounds, just need to fine tune now to get the better consistency as the odd shot was thrown slighly outside the clover leaf, perhaps the crimping may help?

thanks again JP

 

[Muir]

JP: I hope it works out for you. What rifle and caliber??~Muir

 

[JP]

Muir,
I am using a Rem 700 heavy barrel with mod. not my ideal stalking rifle, but it was given to me free (legally etc), I would have preffered a lighter rifle with mod in 30-06, but I was not in a position to be picky! although it is accurate and consistent and thats is what counts I guess. Re-using my old Rem core lokt brass with CCi primer, varget and 150gr nosler partition heads.

First group of five were overlapping except second shot wat 3/4 inch off with 45.1 gr of varget, possibly my inexperience loading?

Second group were better overlapping with one shot 1/4 inch off the group, but this could have been me on the bench rest?

Both groups were on a line overlapping rather than cloverleaf shape, is this the barrel warming up?
All advice welcome.
Cheers
JP

 

[User00014]

when i first got going and ive only been reloading a month or so , i will give some advice i found on here !

when testing your rounds ,do this in batches of 3 -
you will also require a flask or 2 of coffee ,

fire 1 shot , pour a cuppa , fire 2nd shot drink cuppa , fire 3rd

trust me , the cooling of the barrel while drinking ure brew will draw in your gouping !

my first rounds in my 6.5x55 were simlar to ures better than factory rounds , then i started to get the odd flyer or i looked on here and tryed the above advice , it really works stopped the flyer and with a little tweak on the bullet depth in now down to 1/4 " -1/2" @ 100 m !

cheers lee