Roller No. 5 Recrown done

[FatJackDurham]

I got the pilot and recrowned my 7mm Roller. At first, it was really jittery, and left gouges. I figured the 7mm pilot was too small for the bore so today I wrapped it in a little strip of saran wrap, and that seemed to cure the issue. It cut much more smoothly. Unfortunately, that muzzle radius tool continues to be effectively useless. It cuts so slowly, and leaves a burred edge around the muzzle. Although I did get a bevel this time, I basically had to go over it with a stone to get rid of the rim and burr. Better to just use a stone and file to create a bevel.

Here is the BEFORE casting, where the muzzle bells out and the rifling disappears.


After, the rifling is strong and mics out evenly right to the end.


Here is the crown. I wish I could do the factory field crown, but I don't have a lathe. Keep in mind, the bore is .282 from land to land. It looks like a HUGE 45 degree bevel in the picture, but its actually less than a millimeter wide and hard to see without a magnifying glass. You can see some of the burr in the bottom pic. It will get polished out before I add a light rust blue or something.




7mm bullets have been added and hopefully will get here by the weekend. I have four of the original 7mm jacketed rounds to shoot as well to see how it compares with a new crown. However, they mic at .284, and the grooves mics at .287. That might be two wide even for jacketed rounds. The lands as I said mic at .281-282. Predictions?

[Griff]

Predictions?

Accuracy for jacketed rounds should be improved, but... you'll likely have some moderate to excessive copper fouling. If your cast bullets are in the .288-.289 range, you should have much improved results with only minimal leading if you keep the speed down to what's reasonable for your Bhn.

[FatJackDurham]

So far, i cant find any cast bullets larger than .287. They have gas checks so that should help....

[Borregos]

Looks good, keep us posted on how it shoots.

[FatJackDurham]

I will.

On another note, I missed out on a cute little .32 Remington Number 4. There is an auction in town, but they don't take amex, and I don't get paid till friday. It only went for $150. I am sure I could have gotten it for $200. It was a nice octogon barrel, good rifling.....

Oh well. Hopefully I'll get the 38 S&W Hopkins and Allen rifle next month.....

[KWK]

Just to nitpick, the 7mm rollers are not the same as a No.5.

[model55]

J-B non-embedding bore cleaning compound might be of help to you.

[Ben_Rumson]

Nice looking job on the crown, that should help a lot... I don't think that a thou bullet gap on a side is of much concern. If I were loading for it I would only use a flat base bullet as I always got better results with them over the boat tails (even with match bullets) in my Milsurps. Yes the bore does look less than perfect but the pics do make it look worse than it would to the naked eye... and I don't see any copper fouling at all at the magnification of your pics


Recommendations... I'd say have a look at the fore stock barrel channel bedding for tight spots, plus look for anything odd in the hand guard fit... the spring clamp attachment, how much it bears against the receiver & don't forget the barrel band fit...
Your rifle's original loading was the 175 gain round nose jacketed bullet @ 2300fps @ a max 45000 psi so I'd want to be sure whatever load I used in it was a mild one. Perhaps 7-30 Waters loading data maybe useful because it is listed at operating @ 45K psi in the shorter than the 7mm Mauser 30-30 case, so maybe that info might be useful...
Good luck...