Bisley chamber

R1200GS

R1200GS

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Hi I'm trying to confirm whether a 2012 Fullbore pattern 308 reamer is compliant with Bisley rule 150.
I chambered both my Fullbore Target rifles with this PTG reamer if I've got to run a throater in I'd like to do it before next summer. I've got a print but I can't post pictures. Thanks
 
If it's the one that was invented by Pitcairn and crew then it was made for Bisley and the chamber rule. Only problem is that PTG has terrible QA and it likely does not match the print that goes with it. Just about impossible to measure without a comparator. Did you or who fit the barrel? If it was Marshal then you have the assurance that chambers he did have gone to Bisley and must have been checked. The design was probably done with a considerable jump to the lands. I don't believe in that but some do, like Pitcairn I believe.

If you have some RG check that it chambers freely.
 
Thanks Ian
Good point about the reamer possibly not being ground to spec. I know John takes an adjustable throater with him when he goes to England but unfortunately John isn't going this year.
 
The reamer designed for the 2011 Canadian Palma Team (the "Pitcairn and crew" one ;-) has quite a short throat (based on my experience consisting of one observation).

I had a couple of barrels chambered with the one that John Marshall has, and it was too short to pass Bisley's Rule 150. In Bisley this year we had to increase the throat length by 20 thou or so, and that is after we already lengthened a bit.

I quite liked the adjustable throating reamer that John used (pretty sure it was a PT&G?), and am thinking of getting one for myself...

The check they do at Bisley is very straightforward - they put a Sierra #2155 in one of those sample-cases-with-a-slip-fit-neck-and-rod-through-the-base, and verify whether or not your throat allows the bullet to be pushed out to 2.800" COAL by modest finger pressure. Quite easy to duplicate at home.
 
That makes it very easy. I was afraid they were using some gauge that would be very hard for some makers to duplicate. My 3775 JGS Palma reamer designed by Al Warner gives absolutely nuts on 2.800 with that bullet, which it was designed to do. Be aware that not all reamer makers are able to work to a print and what you get can be a crap shoot. I am not sure why some feel they can reinvent the wheel with a new wonder design of reamer.

The PTG throater that is adjustable for length can be ideal in a situation like Bisley. It is a very good idea if made properly and if you have the LOL tool to check with or a dummy at 2.800. If you buy one I suggest you practise and prove it on on old barrel or get a stub partially chambered to play with, you should also remove the ejector if it's spring loaded and/or you have one. You also need cutting oil of some sort and a can of degreaser to clean it up between cuts and calculations. You also need an assortment of bushings. Take your time and lock your friends out of the gun room so you can concentrate. Start with an empty case and the dummy round both in the same new brass. Be sure the empty brass chambers okay and establish a reference point between the action and bolt so you can measure how much you need to move the throat using the dummy. This is obviously easier if the barrel is off the action. Set up the reamer so it can just be felt cutting and then take a measurement and figure out what travel is needed. Adjust the reamer by that amount and away you go. You should probably work in halves, ie if you think you need 50 thou cut 25 and check again, to help prevent screw ups.
 
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I have been on Manson reamers and tried to make them my standard and had some good ones. Lately I have had all kinds of chatter problems with them and have returned a bunch. I am now a JGS guy exclusively. They cost more but they ALWAYS work and are perfect for removing the chatter left by other reamers. Manson does say that his are sharpened differently than JGS and may be more prone to chatter (reading between the lines) great guy to deal with however. Too bad he does not just copy the JGS technique. Gary Eakin is a dealer in Canada. JGS reamer always match the print, don't ask me about PTG!

Manson makes all solid pilot and then reworks if you want live bushing or oil passages for muzzle flush for extra $. Manson does not use a retaining screw, they use a C clip which works fine. JGS only makes live pilot now and they are all ground with oil passages and I think always have been, you need notch the retaining screw for the oil flush which is easy to do yourself although JGS will do it for you, all it takes is a thin cut off wheel in your Fordom. I have not compared apples to apples for cost. I will not use a solid pilot reamer, life is too short, the last one I had would not fit either end of the barrel.

I know, simple question but a long answer.

Ian
 
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