Barrel Indexing

Pete:

You and I must be about the same age with similar experiences...I think exactly as you do!

I am shooting a Shilen Ratchet .177 Barrel that Ed personally did some years back, this is a barrel I tested on a lab gun very successfully, and after some years in storage I fitted it to my Steyr because the barrel Steyr provides good for .250" groups at 50 meters which is good for Field Target shooting, but this accuracy is not enough for competitive BR...At the time I fitted this barrel I had one of those Fiasco Scmidt and Bender 12.5 -50 x 56 FT scopes that were supposed to be the cream of the crop for Field Target but that ended up being discontinued for the many problems and warranty issues...My gun had a scope/mounts/elevation issue and I tested the gun (indexed) for finding the highest point along the vertical axis tor maximum reach without having to modify my scope mounts.

The gun was shot from a vise (indoors) with 7.9, 8.4 and 10.34 gr. pellets, there were no Monster pellets at this time...I used 8 indexing points to start with thinking that I could fine tune my findings later on...The POI for these indexing points didn't vary much for the same weigh pellets and it was interesting to discover that the avg. group size for all points did not change significantly for selecting one point over the other...For measuring the groups I used ASUS electronic targetting systems as used in the Olympics and at the Eley & Lapua testing centers for .22 RF. If I don't remember wrong this barrel is about .002-.003" max. from breech to crown and given the fact that it doesn't improve by indexing and that I have had similar experiences with other .22 RF benchrest barrels, this is why I say that a good straight barrel most likely will not improve when indexed (in terms of accuracy).

Last year I tested a set of regular 3 W.L. Polygons with standard twist and other 2 MI barrels, but was not able to improve what I have, nevertheless I haven't tested slower twists and Hammer Forged for a better comparison, I will do it next spring-summer. You mention a very good point: The same barrel responds very differently under different conditions, and swaping barrels for this matter is a good solution. It definitely is, my problem and yours too is that we don't have that much time left for experimenting...Nevertheless, my search for the "Best in the World Barrel" continues and is endless even though I have an outstanding barrel that only needs a better finger to pull the trigger for winning any competition...

Learning and having fun for as long as it lasts I guess...

Best regards,

AZ
 
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I'm resurrecting this old post because I'm wondering if my RAW TM1000 falls into the category of "guns that don't need indexing", like a Thomas, or if I should at least test it. If so, what is the easiest way to test it? I don't believe this gun has a rotating transfer port so the barrel cannot be simply rotated.

Scrench
 
I'm resurrecting this old post because I'm wondering if my RAW TM1000 falls into the category of "guns that don't need indexing", like a Thomas, or if I should at least test it. If so, what is the easiest way to test it? I don't believe this gun has a rotating transfer port so the barrel cannot be simply rotated.

Scrench


Scrench:

I believe that this topic about Barrel Indexing is very well covered in this thread, I suggest you to read it all...

No Thomas, No RAW, NO GUN for that matter falls into the category of "Doesn't need This or That"...If your barrel doesn't shoot, get another one and keep on looking until you find one that shoots...Don't expect "Miracle Fixes" (indexing) to make a good barrel out of a bad one...If your barrel doesn't shoot, artificial remedies may alleviate some of the problems but it will never make it a killer barrel....

If you ask me, I have been shooting ISSF since the late 60's early 70's and have gone though many dozens of barrels...I have around 24-30 barrels piled up that shoot OK but none of them went permanently into my ISSF or BR competition guns...The barrel I have on my HV RAW is a barrel that was custom manufactured some 20+ years ago and it is not a Poly profile but shoots anything from 8.4. to 13.4 gr. JSB pellets with most accuracy...This barrel shot outstandingly well then and it shoots outstanding now; I have used this barrel in 4-5 competition guns and all of them have been killer guns at any power level...

Bottom line: It takes time and much testing to find a good straight barrel that shoots, once you find one, MARRY it and don't let it go...If you change or sell your gun, migrate the barrel to the new platform and put a different barrel on the gun that you are selling.

If you have a RAW with a transfer port built into the barrel (Hole on the barrel - No Thimble) then be sure that Martin indexed that barrel to its best shooting capabilities and then drilled the port at the precise location for best performance, Martin is an expert in that field and you will not be able to improve what he did.

Regards,

AZ
 
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I would like to buy this barrel

Scrench:

I..The barrel I have on my HV RAW is a barrel that was custom manufactured some 20+ years ago and it is not a Poly profile but shoots anything from 8.4. to 13.4 gr. JSB pellets with most accuracy...This barrel shot outstandingly well then and it shoots outstanding now; I have used this barrel in 4-5 competition guns and all of them have been killer guns at any power level...

AZ

What would you sell it for?

Kim
 
Never wise to intercede in family

But should irreconcilable differences arise please apprise.

kz
 
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