J
JEC
Guest
Krieger offers both .236 and .237 bore diameters in their 6mm barrels. What are the pro's / cons to consider when making a choice. Accuracy comparisons?
jackie schmidt
New member
Jec
It seems the .237 4-groove just caught on. Most shooters that I know who shoot Kriegers use the .237.
Way back when, I tried a 236 bore, for some reason it didn't seem to shoot as well as the .237, so I just never bothered again.
If I remember correctly, back about 10 years ago, Krieger only offerred the the .236 in a 6 groove. The one I had was a 6 groove.
There probably is no compelling reason why one should shoot any better than another, probably has to do with the over all combination and what it likes........jackie
It seems the .237 4-groove just caught on. Most shooters that I know who shoot Kriegers use the .237.
Way back when, I tried a 236 bore, for some reason it didn't seem to shoot as well as the .237, so I just never bothered again.
If I remember correctly, back about 10 years ago, Krieger only offerred the the .236 in a 6 groove. The one I had was a 6 groove.
There probably is no compelling reason why one should shoot any better than another, probably has to do with the over all combination and what it likes........jackie
A friend of mine has a .236" barrel on his 6PPC, I have a .237" on mine. I cut both chambers in both barrels with the same reamer. He consistently gets just over 100 fps faster (through a chrony) than me with identical loads. Is this due to the bore diameter? I simply don't know but it is interesting food for thought.
jackie schmidt
New member
Joe
The 236 bore probably has an initial higher pressure spike. This is not much different than seeing 100 fps difference in two different styles of identicle weight bullets over the same powder charge.
As an example, if you are getting 3400 from a Barts Ultra, or Bruno Boat Tail, (examples of 00 bullets), and switch to a Fowler Style Bullet, (7.5 o-give, relative straight shank), you will see 3500.
I have always considered .237 4- groove Kriegers "slow barrels". They tend to act a little loose, especially when combined with one of the 00 bullets. That is why they tend to respond so well to upper end loads........jackie
The 236 bore probably has an initial higher pressure spike. This is not much different than seeing 100 fps difference in two different styles of identicle weight bullets over the same powder charge.
As an example, if you are getting 3400 from a Barts Ultra, or Bruno Boat Tail, (examples of 00 bullets), and switch to a Fowler Style Bullet, (7.5 o-give, relative straight shank), you will see 3500.
I have always considered .237 4- groove Kriegers "slow barrels". They tend to act a little loose, especially when combined with one of the 00 bullets. That is why they tend to respond so well to upper end loads........jackie
F
Frank Green
Guest
For the most part the different bore size has no bearing on accuracy and or barrel life.
There seems to be a general consensus among shooters that the .237 bores are a little more forgiving or accurate. Maybe it has to do with the bullets being fatter (.2435 as an example) that might make the difference.
As far as the .236 bore and more velocity. I would agree with it. Anytime you decrease the surface area of the bore/groove size (tighten things up) with the same load you will increase pressure which can result in why you are getting the higher velocity. Keep in mind there are many variables.
I use to use mostly .236 bores on my high power guns but have switched over to .237 bores. I'm more worried about bullet failure for a long range shooting than anything else and I don't see the .236 bore helping at all. I've shot the .236 and .237's and again don't see a difference in accuracy for the most part and also have shot tight bore .30cal. barrels and standard bore barrels with the same conclusion.
If I would look at our s/n history on the 6mm's I would say it is a 65/35 split and the .237's are more popular over all bench and high power. For the bench shooters it is more like 75/25.
Later, Frank
Bartlein Barrels
There seems to be a general consensus among shooters that the .237 bores are a little more forgiving or accurate. Maybe it has to do with the bullets being fatter (.2435 as an example) that might make the difference.
As far as the .236 bore and more velocity. I would agree with it. Anytime you decrease the surface area of the bore/groove size (tighten things up) with the same load you will increase pressure which can result in why you are getting the higher velocity. Keep in mind there are many variables.
I use to use mostly .236 bores on my high power guns but have switched over to .237 bores. I'm more worried about bullet failure for a long range shooting than anything else and I don't see the .236 bore helping at all. I've shot the .236 and .237's and again don't see a difference in accuracy for the most part and also have shot tight bore .30cal. barrels and standard bore barrels with the same conclusion.
If I would look at our s/n history on the 6mm's I would say it is a 65/35 split and the .237's are more popular over all bench and high power. For the bench shooters it is more like 75/25.
Later, Frank
Bartlein Barrels