May 17, 2010
So I was driving home from work friday, glad for another weekend. I got to wondering about the possibility about what will I do if I get asked to test one of EWK's barrels.
So the following is more or less just free form thoughts, not really and more:
I have zero tools/instruments to do any scientific measurements. The only thing I can really do is to shoot the EWK barrel and a stock DW barrel and note any differences. I possibly can tell if there IS a difference ... but I wont know what the cause of the difference is.
How to test:
Shoot 6 rounds via DW, then shoot 6 rounds via EWK, using any possible means to reduce variance. Use a support, equal distance, same target, same shroud, same ammo source.
If the EWK barrel produces an equally tight group, but the group is not centered the same as the DW. What does that mean?
If the EWK group is not as tight as the DW group; what does that mean?
If the consistancy of the EWK group is less .. could it be less?
What would be the effects of the following as seen on a target?
Barrel forcing cone not perpendicular to the barrel; other end?
Forcing cone too tight/loose
Forcing cone to long/short
lands/grooves too shallow/deep
what else could be "wrong" with lands/grooves?
Backwards twist?
barrel material too hard(brittle)/soft
final inside diameter too small/big
Thats about all I could think of. I just shoot revolvers... I am not a machinest, so I just want to be able to return information back to EWK other than "yeah I shot it and it seemed fine to me". Something methodical.
Soap Box, Ballot Box, Ammo Box
in that order.
4 Monson Model 15's
1 Palmer FB 15
1 Rossi 357 Model 92 (lever)
1 CZ 75B
October 13, 2009
You, Jody and Jagg are on the list since 'ya all volunteered, so its good you're thinking! Basically for testing, need ya' just to shoot it to see how it groups and if you could run some plain 'ol lead bullets to see if leading up is an issue. And of course watch for other stuff...feedback how it performs compared to the DW's would also be great! I want them to be at least as good as the good DW barrels.
Here's some of my thoughts, since I'm just getting into making gun barrels, some may be off, so would appreciate pointing out any of my thoughts that might be messed up!
"I have zero tools/instruments to do any scientific measurements. The
only thing I can really do is to shoot the EWK barrel and a stock
DW barrel and note any differences. I possibly can tell if there IS a
difference … but I wont know what the cause of the difference is."
Perfect reason to buy a chronograph! That would be quite interesting measure the velocity between DW and EWK barrels, but if you can't, its no biggie!
"Shoot 6 rounds via DW, then shoot 6 rounds via EWK, using any possible
means to reduce variance. Use a support, equal distance, same target,
same shroud, same ammo source."
That sounds like a great plan to me!
"If the EWK barrel produces an equally tight group, but the group is not
centered the same as the DW. What does that mean?"
If that happens, that would mean you would have an off-center barrel. (Bore not concentric to OD of barrel) Only other reason would be using different shrouds may locate a little bit different, affecting grouping.
"If the EWK group is not as tight as the DW group; what does that mean?"
I have more work to do.
"If the consistancy of the EWK group is less .. could it be less?"
That's what we want! Yes it could very well be less, especially if you have a non prime DW barrel.
"What would be the effects of the following as seen on a target?"
"Barrel forcing cone not perpendicular to the barrel; other end?"
I'm not really sure on that one, it would seem in my mind to cause an uneven start to the bullet-ie. top end of the bullet would start to catch the rifling before the bottom side of the bullet would. But if all the other factors in the barrel are good, the bullet should stabilize as it travels down the barrel. But then if its an extremly non-perpendicular forcing cone, it would weaken the barrel. But not planning on doing anything like that.
"Forcing cone too tight/loose"
Too tight-bullet would have trouble starting in the barrel, and cause a lose in accuracy as the bullet will have to more suddenly find and engage the rifling. Hard on breach end due to the force of the bullet trying to start. Too loose, weak breach end (ie. possibly cracking at the start of the forcing cone due to lack of strength.)
"Forcing cone to long/short"
With different angles that the forcing cone is made to, the length will vary. Might offer different angles on the barrels as an option as it seems lots of people have preferances as to different angles-I can't seem to find any agreement on what angle works best. That's why we have to pick one and see what happens. If the barrel isn't working too well and all other factors look good, we know which parameter to change.
"lands/grooves too shallow/deep"
Larger bore/groove diameter, less grip on bullet, and in the narrow range either an increase of decrease in velocity. (Think less resistance to travel, and on the flip side, loss of "sealing" of the pressure behind the bullet.) Too small same as above, except too small, overpressure-not good!
"what else could be "wrong" with lands/grooves?"
Too rough, (ie. leading/excessive heating) Tapered/inconsistent bore/groove diameters-lose of accuracy.
"Backwards twist?"
Not sure what difference that would make, physics guys?
"barrel material too hard(brittle)/soft"
Strength issues in both cases and also wear issues if you get too soft.
"final inside diameter too small/big"
That would be the bore/groove diameters, see above.
Phew, hope that makes some sense. Need to get back to work so we can have some barrels here soon!
Eric
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November 17, 2008
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May 2, 2009
I figure if I'm called into duty I'm going to take some of my hunting loads and my chrony, and torture test something ... Then once the rifling is smoothed out, I'll run some nice target loads in them.
Send me a SM setup and I'll pull out that box of factory PROOF loads I have ...
SHOOT
October 13, 2009
Well, these round bars with holes that have helical paterns on them are apprearing, so we should have something ready soon to see if we can call them gun barrels.
For length, what works best for 'ya guys? Hopefully you have a 6 or 8" shroud as that would be easiest for me to make right now so we can test 'em.
Thanks!
Eric
May 17, 2010
EWK_Stuff said:
Well, these round bars with holes that have helical paterns on them are apprearing, so we should have something ready soon to see if we can call them gun barrels.
For length, what works best for 'ya guys? Hopefully you have a 6 or 8" shroud as that would be easiest for me to make right now so we can test 'em.
Thanks!
Eric
I have 1 8" V and 3 6": 6V, 6VH, 6V in SS.
The SS has VERY few rounds through it (less than 15), though I do not know how to compare the two materials.
My slight preference would be for the 6" as I have pretty much stopped shooting the 8", for no real reason, but really I can test either.
PS: Just rememberd the 6VH is in the shop getting a hot blue, wont be back for several months.
Soap Box, Ballot Box, Ammo Box
in that order.
4 Monson Model 15's
1 Palmer FB 15
1 Rossi 357 Model 92 (lever)
1 CZ 75B
glad to hear your still putting in the time, effort and expense to bring this all togeather! WHEN you get to the mag and super mag calibers put me down for testing any of the 357sm,375sm, 41mag, 44mag and the 445sm. have some in 6" and 8" shrouds. Don't have a crony but do have shooting range and reloading ability for all of the above. Hang in there Eric.
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