I got some more feedback today on the 7-08 with the Krieger barrel that was lapped. The owner told me he had gotten a five shot 9/16s inch group to which I thought good,that is in the half minute area it had been shooting after the lap job and then he said after a pause............... at 300 yards!
He shot an F class event last week end and was plunking 10s and x's until shot six and dropped a couple low into the nine ring and thought , what to heck then he said he felt a puff of wind on his face from from 12 o'clock and realized he had missed the wind call. He adjusted and started plunking tens and x's again. It's fun to hear when things go right but this is not always the case and when one does gun work your either a genius or and idiot who doesn't know anything!
I hand lapped an 1860 Colt Pietta copy this week end. Got some taper put in it and got rid of a tight spot mid barrel and a loose muzzle. It finished up with a bore diameter of .4365 and seven grooves of .4585. The chambers need reamed and honed as they vary .003 from biggest to smallest so will need to get an order off to Brownells for the stuff to do it.
Pictures of charged lap and .436 plug gauge in muzzle and breech after lapping.
You do not have the required permissions to view the files attached to this post.
I used a slug from my .43 Spanish to drive through the bore and then run on the Powelly gauge to calculate the groove diameter.
Plug gauge in largest cylinder chamber.
You do not have the required permissions to view the files attached to this post.
It's always cool to make a rifle shoot good that someone has been at odds with. A relative brought an older gentleman here and he had inherited the Winchester 25-20 he shot as a boy. The older fellow wanted to shoot it again before he died. The rifle had been stored in a barn and mud dobbers had filled the barrel. I cleaned it for hours, got everything working and then loaded some lead 25-20 rounds . The old fellow hadn't shot the rifle since he was 10, but put it to his shoulder and hit a steel pig target dead center at 25 yards. That was it. He thanked me and walked to the truck.
There are those that talk, and those that act. Make a choice.
I came up with an idea of how to make a chamber hone last night. I'll turn a body of Delrin to smallest chamber diameter and cut a Key way in one side length ways. I'll grind and fit a piece of emery stone with a flat" c" shape spring under it to provide even tension then thread the center for an axle to be run with a flex shaft in a hand drill motor. Same basic idea of how shot gun chamber and choke hones work. This should open and even them up to uniform chambers about .001 over the groove diameter. It will be slower than a reamer but much cheaper and safer to use as it will cut slowly and be self centering.
I lapped the chambers of the 1860 revolver this week end and got the variance down to less than .001 with the average at .4465. I made a mistake when I said the groove diameter back a few posts was .4585. It was supposed to read .4485. So the chambers about .002 less than the groove but are pretty close to each other and testing will tell the story if I need open them up to groove diameter or not. The hone cuts very slow but sure is a lot safer than a reamer and cheaper as well. If I need to ream I probably will make a half reamer myself, for the job.
It was interesting to see how out of round the chambers were and the differences in chamber wall contours from the gang reaming at the factory. The chambers were blued on the interiors and the hone shines up and reveals where the chambers are not perfectly round and smooth.
This is the hone that was fabricated from some plastic rod stock I had on hand with a cutting side and a leather strip on the opposite side for tension.
You do not have the required permissions to view the files attached to this post.
The cutting strip was made from greytrix cuttng rubber fashioned from a wheel of the proper thickness and the tension was provided from a strip of leather on the opposite side with paper shims to elevate as needed. I started by shaping a broken triangular stone on my Green emery wheel grinder but these kept breaking so decided to try the abrasive wheel cut to fit the hone groove and that worked very well.
All of these Colt copies from Pietta come with under size chambers for some reason and most are out of round and not uniform of diameter. I find this in modern revolvers as well but am perplexed as to why the chambers would be cut so under groove diameter as most shoot better if of or a bit over groove diameter.
Do any of you guys mess around with these percussion revolvers? I sure get a kick out of shooting them and have been competing with them for 35 years. I've yet to have a chain fire but am told it will probably happen sooner or later.
Their accuracy is actually quite phenomenal when one sees how the open top guns are fabricated!
The 1860 was the preferred revolver of the civil war period as far as reliability and ease of use but the 1858 Remington is my preferred competition gun. Both are from Pietta but have had extensive mods made for accuracy. My 58 Rem/Pietta is actually more accurate than my Ruger Old Army and they are always plenty accurate right out of the box.
You do not have the required permissions to view the files attached to this post.
