comp indexing?

[mwx40x40]

I was just wondering if anybody else out there ever had any problems indexing their comp. I just put a Titan comp made by SJC on a White Oak Armament 18" SPR barrel. With the washer that came with the comp when hand tight it is just past where it ought to be . Looking down the barrel as if shooting the rifle the comp is indexed to about 11:00 o'clock. If I tightened all the way with a wrench compressing the washer it ends up between 9 and 10 o'clock. I tried a lock washer that came with a birdcage flash hider and hand tight is almost perfect. But with firm grip and no tools it will index not quite to 11:00. Does anybody offer different thickness's of washers (ones that would match the .750" dia bbl)? Or will I have to have something turned down?

[shred]

You could get a peel washer. Those can be split into little tiny slices so you can tweak the indexing all you want. Some AR comps come with peel washers and the instructions don't tell you.. I learned that one a long time ago, so you might want to inspect the one you have very carefully.

[Dan Sierpina]

Where does it wind up, without any washer? It might work fine that way. Or, if there is minimal gap, some Loctite retaining compound will hold it in place.

[Bear1142]

mwx40x40,

The washer that came with your Titan comp is a peel washer. You can peel off small portions of the washer to properly index the comp.

Erik

[mwx40x40]

mwx40x40,

The washer that came with your Titan comp is a peel washer. You can peel off small portions of the washer to properly index the comp.

Erik

Thanks guys , I will check out the washer a little closer. Will it peel into more than two parts?

Mark

[shred]

If it's a true peel washer, it'll peel into hundreds of slices.

[Bear1142]

How about some pics when you done?

Erik

[benny hill]

Use blue loctite to keep the comp from moveing & ease of removeal

[TRUBL]

You can seperate the washer with a knife edge....or you can do what I've done in the past....hit the edge of the washer with a bic lighter, that will make it seperate as well.

Tim

[kurtm]

Tim:

That is the BEST tip I have ever received!! I have always had trouble seperating in small increments, just tried your method and WOW. too cool!! Thank amigo! KURT

[Pclark832]

Sorry to hijack your thread but..

I just baught the benny comp from JPrifles. What kind of washer does that come with? There were only two parts in the kit the comp and a washer of some kind. When i hand tighten it it gets to about the 2'clock position. almost perfect.

[Gregory_k]

Sorry to hijack your thread but..

I just baught the benny comp from JPrifles. What kind of washer does that come with? There were only two parts in the kit the comp and a washer of some kind. When i hand tighten it it gets to about the 2'clock position. almost perfect.

Mine came with a crush washer which is good for 1.5 rotations after snug.

[Pclark832]

Sorry to hijack your thread but..

I just baught the benny comp from JPrifles. What kind of washer does that come with? There were only two parts in the kit the comp and a washer of some kind. When i hand tighten it it gets to about the 2'clock position. almost perfect.

Mine came with a crush washer which is good for 1.5 rotations after snug.

Thanks!

[Bear1142]

hit the edge of the washer with a bic lighter, that will make it seperate as well.

I will have to give that I try next time. Thanks for the tip, Tim.

Erik

[ChrisMcCracken]

How exactly does one index a comp?

[GentlemanJim]

Well, it can be done several ways

You can use a crush washer and just clock it in, this is easy and works fine

You can use shims (peel washer) to adjust its index

Or you can do it with no washer or shims by turning the comp in a lathe to a precise fit

Many barrels have a shoulder at the bottom of the barrel threads, for those the comp has to be back bored to clear the shoulder

The barrel thread is one half inch by 28 TPI

So one full turn is .0357"

One half turn is .0178"

One quarter turn is .0089"

By screwing the comp down snug, you can find how much material has to be removed to clock it correctly

Or you can clock it to the nearest thread, and use a feeler gauge to find the approximate value to turn or shim

Keep in mind when measuring this way to find how much material to remove, you subtract that value from .0357

Always remove a little less material than you think you need

Jim

[outerlimits]

doing it the lathe way is best. when i ordered a JP barrel/comp a few years ago, when i got it i swore that barrel/comp was one friggin piece. you really have to look closely to find the seam.

[Nuke8401]

Eruco may be asking why/how as in what direction is a "comp clocked".

The basic jest is that a comp will push in one direction (in addition to recoil it also affects muzzle rise) and for a right hand shooter it is "clocked" close to 1:00 or 11:00 for a left hand shooter to cancel muzzle rise and the effect of the shooter's grip. Of course many will say clock each comp for the specific gun, comp, and shooter so yours might not be at 1:00 or 11:00. So any given comp may/should come with directions.

Others may correct / clarify my post.

David E.

[cardiackid]

I clocked mine at 12 because you never know when you're going to be doing offhand shooting. The last thing I'd want is another variable adding to the minor handicap of shooting support side (until you get really good at it, that is).

[ChrisMcCracken]

Well, it can be done several ways

You can use a crush washer and just clock it in, this is easy and works fine

You can use shims (peel washer) to adjust its index

Or you can do it with no washer or shims by turning the comp in a lathe to a precise fit

Many barrels have a shoulder at the bottom of the barrel threads, for those the comp has to be back bored to clear the shoulder

The barrel thread is one half inch by 28 TPI

So one full turn is .0357"

One half turn is .0178"

One quarter turn is .0089"

By screwing the comp down snug, you can find how much material has to be removed to clock it correctly

Or you can clock it to the nearest thread, and use a feeler gauge to find the approximate value to turn or shim

Keep in mind when measuring this way to find how much material to remove, you subtract that value from .0357

Always remove a little less material than you think you need

Jim

Judging from that excellent answer, I think it could be said differently: Send the upper back to Jim.

I'll be in touch to see about getting your new comp fitted to my FB15.

Thanks!

Chris

[kamikaze1a]

My 2¢, I don't like putting too much torque on the end of the barrel so usually use a combination of peel washers and crush washer if I can not index the comp. I've even cut shims out of soda cans and stacked to what I needed. I've not any evidence that crushing that washer affects anything, just my choice...

[carbon9]

My 2¢, I don't like putting too much torque on the end of the barrel so usually use a combination of peel washers and crush washer if I can not index the comp. I've even cut shims out of soda cans and stacked to what I needed. I've not any evidence that crushing that washer affects anything, just my choice...

If you don't like cranking down on it you should try some serrated Belleville Washers. You can stack them front to front or back to front whichever you need to achieve proper timing or loading. I like the fact they act as a spring to hold tension and provide stability. McMaster-Carr is always your friend, you can get black or stainless ones.