how much of a difference does this make?

On rifle reloads for bottle neck cases it makes seating the bullets easier. I've been doing it for so many years that it's just part of the loading procedure.

For loading cast pistol ammo where your belling the case it probably makes no difference. For loads for an auto pistol that headspace on the rim don't do it.

On rifle reloads for bottle neck cases it makes seating the bullets easier. I've been doing it for so many years that it's just part of the loading procedure.

For loading cast pistol ammo where your belling the case it probably makes no difference. For loads for an auto pistol that headspace on the rim don't do it.


I gues I should have been more specific. I trimmed a bunch of .45-70 rounds and I did not purchase a Camfer and Deburring tool should I get and use one? Does it effect accuracy or feeding?

Thanks

I gues I should have been more specific. I trimmed a bunch of .45-70 rounds and I did not purchase a Camfer and Deburring tool should I get and use one? Does it effect accuracy or feeding?

Thanks

Straight walled rifle cases like pistol cases usually come with three dies. One of those dies bells the mouth of the case to accept the bullet.

For those kind of cases camfering and deburring won't do much if you havn't trimmed the cases. When you trim cases a square face is left on them and I always camfer and deber.

Got to say I've hardly ever trimmed my 44 or 41 mag cases though.

Get the tool. The Lee one is really inexpensive, though I like the feel of the RCBS tool better. In a pinch, you can substitute any chamfering tool or countersink to do the inside of the case mouth, then deburr the outside with a fine file. The wire edge burr left by the trimming process can be wide enough to interfere with bullet release in some chambers, and thereby raise pressures. This isn't likely in a commercial .45-70 chamber, but even so, you'll find the brass burrs can break away from the case in little rings during firing and be left in the chamber. Should they fail to be blown out, they may accumulate at the mouth of the freebore, causing the same potential pressure threat.

If you are loading cast or swaged lead bullets, you will also discover the sharp edge on the inside of the case can shave lead. This affects both accuracy and pressure if it winds up in the wrong part of the chamber. Belling the case mouth will avoid that, but you have to bell more if you haven't chamfered, so case life is reduced. Running the case over the sizing die expander a couple of times after trimming can burnish this edge down, but the internal brass ring often still breaks away. It likely launches with your bullet, but isn't helping consistency any. If it breaks away in some cases and remains in others, you can get a start pressure variation between the two that affects accuracy, particularly at longer ranges. This will be hard to see in .45-70, but since chamfering and deburring are easy and not too expensive to do, why not make ease of reloading and consistency better by doing it?

Nick

Have had the casemouth actually scrape some copper jacket material off the bullet during seating due to insufficient chamfering. Altho I did chamfer, I obviously had not chamfered enough on those .308 WIN cases. As SOP, would chamfer any case that has been trimmed. A hand chamfering tool is not all that expensive and will last you forever. Take the guys' advice and get one.

Have had the casemouth actually scrape some copper jacket material off the bullet during seating due to insufficient chamfering. Altho I did chamfer, I obviously had not chamfered enough on those .308 WIN cases. As SOP, would chamfer any case that has been trimmed. A hand chamfering tool is not all that expensive and will last you forever. Take the guys' advice and get one.


Thanks guys I am ordering one

If you haven't already ordered,you'll want a big bore chamfer/deburring tool as the regular size is too small to deburr the 45/70 case. I use the Lyman version.
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=285108