45-70 sizing

[brad925]

I am just wondering how big of a boolit can I push down the barrel. For my H&R BC I ran .460 dia 405 Lee HB on the advice of another on this forum with the ideology that if it will chamber it will shoot them. By the way the groove dia. was .457. My Uberti High Wall is .456 according to Cimerron Arms which is the distributer and this size was verified. I chambered one of the loads for my BC which it chambered fine and shot a nice tight cloverleaf at 50 yds with it. Considering I could barely make out the mark I put on the cardboard to aim at I was satisfied. My question is running a .460 diameter boolit through that gun with a .456 groove diameter asking too much of the boolit to squeeze down that much. Also I am using 35.0 grs of IMR 3031.

[detox]

Ask your spent primers. Did you read your primers? Are they showing signs of high pressures (excessive flattening, etc)?

[Crusty Deary Ol'Coot]

My thought is you have no problem.

As said, watch for presures and don't start at the top of the load charts.

Example, it is normally thought that a persons bullets should not be forced into the lands when chambering a cartridge due to possible pressure problems.

But, there are folk who normally Breach Seat their cast bullets, pushing them firmly into the lands before chambering the powder charged cartridge case.

I have, during the process of fireforming 30/06 brass to 30 Gibbs, seated jacketed bullets tight into the lands to hold correct head space during the fireforming.

These are standard practices and in fact, you can load jacketed or cast loads in which the bullet is always seated tight into the lands and do so with complete safety.

However, you do not start at the top of the load charts, but develop/workup the loads with the bullets in this position and therefore, providing you are prudent and watchful, do not exceed safe pressures.

As DETOX says, "did you read your primers"? However, primers not always being relyable indicaters of high pressures, you must also watch for other signs such as hard case extraction or other signs of excessive pressure.

Crusty Deary Ol'Coot

[DLCTEX]

A friend shot hundreds of my boolits sized .459-60 through his H&R BC with good results.

[HangFireW8]

My question is running a .460 diameter boolit through that gun with a .456 groove diameter asking too much of the boolit to squeeze down that much. Also I am using 35.0 grs of IMR 3031.

If it's not shaving off lead at the throat, and you're not getting high pressure signs like tough extraction, blown primers, etc., you're good to go. Lead obturates fairly easily.

[runfiverun]

you seen the groups.....

[cajun shooter]

I shoot nothing but .460 bullets through my H&R BC although my barrel slugged at .458 and I shoot nothing but 2F BP and 500 to 535 grain bullets.