QUESTION ABOUT CRIMPING

Mica · Feb 26, 2011

I am new to reloading, as of 3 days ago to be exact. I Have a 270 pump, Do I need to buy a special die for crimping my rounds. Or do the dies have that built in. I was reading in my loading book that pumps andsemi auto need to be crimped.

Pepe-lepew · Feb 26, 2011

It is built in the die. To use it and adjust it, read the instructions carefully. It is optional since many bullets in 270 do not have crimp grooves.

Mica · Feb 27, 2011

thanks for the info

Spitpatch · Feb 27, 2011

Howdy Mica,

I don't think crimping is absolutely necessary for a pump-action gun. The quick forward chambering that occurrs in a semi-auto would not normally happen in a pump. I don't crimp for any rifles except tube-feed guns, and lead/blackpowder loads: not even for semi-autos. Whatever you do, do NOT crimp on a bullet that has no cannelure (crimping groove).

Crimping might be advisable if you are very hard on your ammunition in transport (rattling around in pockets, etc.). Another application would be if rounds were left in the magazine of a rifle of heavy-recoil during a long hunt, and the first round was replaced and fired again and again leaving the same old guys in the box bringing up the rear. In that case, a cartridge repeatedly pounded by recoil while it rested in the magazine might allow its bullet to walk rearward in the case if it were not crimped.

If you have good reloading dies that size the entire neck properly to hold the bullet firmly in the neck, crimping is not needed for your pump .270. Lee Collet dies can result in the neck of the brass not holding the bullet very firmly if not used correctly, and may convince some handloaders that they need a crimp.

Mica · Feb 27, 2011

thanks, thats good to hear. this is the first pump rifle i have ever had and was concerned. still trying to get used to the feel of it. I cut my teeth on bolt actions since i was a pup. the only reason I have one is because I couldnt pass up the deal.

HollisOR · Feb 27, 2011

Lee's factory crimp die is probably one of the best deals on the market. As it was mentioned, you can not crimp a jacketed bullet if it does not have a groove. Also, if you crimp to hard it could bulge the neck. The other thing, cases need to be the same length. A shorter case may not crimp, a longer case may bulge the neck.

On single shot firearms, crimping is not necessary.

Mica · Feb 27, 2011

thanks, I have a rcbs loader and I have been doing alot of reading on the subject of reloading. Im just about to try my first shell. I still need to pick up a micromiter and a case trimmer though. I baught some new winchester brass for my first runs. I cant wait to try them out.

Spitpatch · Feb 28, 2011

You don't need a micrometer for handloading until you get into the technical stuff (real techinical stuff). A caliper (is that what you meant?) is almost necessary, but a simple graduated case length guage is all that thousands of good handloading guys used for years and years. You have eliminated about half the snags new guys run into by your choice of RCBS gear. You'll never have to upgrade.

Don't discount that good 760 Remington. My brother swears by his 760 .308, and he's been in Alaska for 30 years. I took a buddy up there for Caribou, and he was agonizing about having to buy a bolt gun to go. I convinced him to take his 760 .270, and save his money. His caribou ended up just as dead as the ones shot with bolt guns. (And his caribou was a bit bigger than a couple of those). He spent his bolt gun money on taxidermy.

Mica · Feb 28, 2011

that is good to hear. I will pick up a length guage then. I decided to get comfortable with my 760. especialy after my hunting buddy up in north Idaho. pined my ears back over the phone for thinking abuot trading for a bolt.Glad it wasnt in person. LOL

iusmc2002 · Feb 28, 2011

Not to appear ignorant, or open my mouth and prove it, but why shouldn't you crimp a bullet without the cannelure? What would it really do?

AMProducts · Feb 28, 2011

+2 on the lee factory crimp die, it's one of the few good products they make, and it's hard to beat the price. If you are running cases of different length (winchester factory brass, the stuff they sell to reloaders is notoriously bad) Taper or Roll crimping can very easily bulge the neck, or the shoulder. If your gun is magazine fed (from a traditional box magazine), you shouldn't need to worry about crimping, provided you have adequate neck tension, if your gun is tube fed (like most .30-30WCF) you need to crimp and need to use round nose/flat nose bullets and you MUST CRIMP! IIRC you don't really need to crimp too heavily using the gun you said... And if you got a good deal, great! Pump hunting guns are a personal favorite of mine, they are faster than a bolt, and perform as well as a semi, at a substantial savings.

To answer IUSMC2002's question, if you crimp a bullet without a cannelure, the metal has no where to go, in cases of taper/roll crimping, usually you will just bulge out the case neck, and you will have to pull the bullet, resize the case, and try again. If you are using a factory crimp die (the lee collet type discussed earlier) it will usually deform the bullet ruining accuracy. I do a lot of loading with frangible bullets, and they need to be crimped, but have no crimp groove, so it requires very careful adjustment of the FCD to get right. Too much crimp, or a case that's too long will usually cause the crimp to be too heavy and it will break the bullet in half.