Slugged a couple barrels today

[161]

I went to town today an picked up a box of.375 and .490 round balls. I slugged the 1894 357 and it measured about .356 .3565 with rifling grooves of .346. I slugged my 45-70 and it measured .458 with rifling grooves of.446. Do these measurement sound right? It's the first time I've done this. If they are right is it correct to assume that a cast .358 should shoot well in the 357 and a cast .458 should shoot in the 45-70?
Thanks
Warren

[northmn]

Many like to have the cast about 001 or 002 larger than the bore diameter. Seems to give better accuracy and less leading.

DP

[Piedmont]

Warren, Doesn't sound right to me. I've slugged one of each and the rifling in modern day Marlins was much shallower than that for me. The groove measurements don't sound out of line but unless Marlin changed from button rifling I don't think the bore measurements are correct.

BTW you have your terminology messed up, the groove dimension is the bigger one.

[Bass Ackward]

I would say that it depends. I have been looking for a 357 lever for a couple of months. My local shop got an 1894C in day before yesterday.

I flew right down, (never a good bargaining tool) dropped the lever and shined the light in, and my calibrated eye balls went into shock. I thought I was looking down my 336SC. Looked like teeth they were so bold. So that would have slugged VERY nicely to what you mentioned.

I was so excited I was reaching for the CC and then reality set in as I saw the muzzle. Somebody had put it down on concrete and moved it around. Then they drug it at an angle over concrete. All the screws were buggered, every, single one. There was an unsightly scratch on the action.

There was a 1/4" gap that you could see daylight around the bottom portion of the tang.. You could literally see the floor looking down from the top. When they test fired it, a chunk had flown off the top where it took the pressure. The fore stock had broken chips where it was not properly fit and jammed onto a too wide barrel. And I wouldn't call the barrel band anywhere near a close fit as you had to almost aim under it.


I was so dejected. So they decided to look at the other four that they got in. Three of those were defective in major ways also.

Looked like morale was right out the window with this plant relocation. So look closely for awhile.

[161]

I should have mentioned the 45-70 is a Pedersoli Sharps not a Marlin. I'm surly going to sound like a fool but if a barrel measures .356 or .357 how can a .358 boolit pass through without leading? Also what you're telling if I understand correctly the bore size is the measurement the rifling cuts in the slug? .446 in the 45-70 and .346 in the 357? Sorry for the elementary school questions but better to ask then break something. By the way I found a used 1894 44 mag. pre-safety I traded for last night. Don't even have the ones I already have shooting to my liking and I drag home another.
Thanks for your help
Warren

[northmn]

Actually due to the ability to seal gases, over size CAST bullets work very well in a rifle and lead less. There is a theory that a cast bullet if properly sized to a bore may not need lube. I use 310's in my 30-30 which is not uncommon. Most want that type of fit. There may be something to the increased resistance before the bullet swages sown in the barrel giving more consistant velocities? Most like at least 001 oversize and some just use as cast whcih could be more.
According to once source I ahd on the history of Savage 99's the 303 and 22 Hi Power wer purposely designed to be oversized as it increased pressures and therefore velocities. This was with jacketed bullets.

DP

[Piedmont]

161, Think of it like this. Traditionally a hole was drilled in the barrel (BORED). Then the grooves were cut in deeper with a cutter. If you remember that you'll never get it wrong again. Most of us try to size to barrel throat diameter which is larger than the groove dimension. This seals gases better and starts the bullet more straightly.

[missionary5155]

Good afternoon
To me far more important is the throat measurment which is many times far larger than the groove diameter. Fill the throat and you have filled the groove. Fill the throat and you have sealed the gasses at the boolit base.
I generally plan on boolits that will cast Throat diameter + at least .001.

[161]

I talked to an old gunsmith today. He told me I shouldn't expect much out of a new barrel until I've shot about 100 jacketed out of it. He said the new barrel needs the rough edges knocked off before it'll shoot cast well. Any thoughts?
Warren

[felix]

Yes, that is true, but sometimes you can get a brand new barrel that shoots boolits well right off. There is no rule here when barrels are made with modern machinery. The hammer forging machines made within the last 10 years can make a good barrel cheaply. Other methods can make an excellent barrel, but at a price few of us are willing to cough up. ... felix

[northmn]

With muzzle loaders we polish them with things like Scotch Brite. Some use different compounds liek JB for that purpose. Prevents torn patches.

DP

[161]

I slugged two more barrels my 336 35 Remington Microgroove, and the 1894 44mag I just picked up. I can definitely see the difference between the Microgroove and the new (ballard) spelling? The 35 Rem. is .3575 and the 44 is .4295. The rifling on the 35 looks so small compared to conventional rifling. All new stuff to me. I guess I just got lucky when I started casting for the .40 cal. I bought a 175TL and started casting they shot great. Rifles must be a different cat.
Warren

[MtGun44]

+.002 to .003 for rifles seems to work well.

Bill

[NHlever]

My fairly new Marlin 1894C barrel is on the tight side too, and that both surprised, and pleased me. There are a couple of very minor spots in the bore where it feels a bit larger but there is still resistance on the slug as I tap it down the barrel. It is pretty uniform at .3563. I haven't shot it much yet, but my initial testing has shown a lot of potential. I have .357, .358, and .359 diameter boolits on hand so I just have to get some medical stuff out of the way, and then the fun can begin! Good luck with yours!

[161]

I think I'm going to get 100 jacketed an run them down the pipe then give the cast another go around. Is there a thread already started or somewhere I can learn how to measure the throat of a rifle?
Thanks again for the help
Warren

[GH1]

I'm not surprised your Marlin is a little bit tight, mine is too. My marlin shoots .357 cast bullets just fine, but they lead in my Taurus revolver. Pain in the but to scrup out, let me tell you. SO I switched to .358's in both guns and have now problem with the larger boolits in either. Tight fit = no lead.
GH1

[161]

Thanks for the reply I read others talking about measuring the throat. How do I do that?
Thanks
Warren