Caliber question!!

speedystu

Well-Known Member
Hello all! I have just been granted my 6.5x55 and have a moderator proofed to .25 cal! Now will this mod be appropriate for my 6.5? Or is it cutting it to fine!
Many thanks stu.
 
If the moderator is conditioned on your ticket as a .25 moderator then thats what it is, despite it being perfectly suitable for other calibres.
It raises an interesting question though. If a .30 cal mod is proofed at .243 and on your ticket as a .243 mod can you legally use it on a 30 cal?
 
yes, it can.
I have in writing from L&B that the 6.5mm bore PES I have is fine for 243, .22, .17
there is no restriction that I am aware of, that stops you using one mod on many rifles, so long as the moderator is on your FAC it is not partnered with any particular rifle

there initially was a bit of a balls up on mine as the PES was entered on my certificate as a "small bore moderator" which implied "rimfire" despite the fact I had got it for my HMR and was also using it on my .243.

I also have a slot for a "full bore moderator" ...whatever that is!

That said my 6.5mm bore moderator gives me 0.25mm clearance for a .243.
I would clarify that your .25cal moderator has a minimum of 7mm bore before you fire a 6.5x55 bullet through it
 
I also have a slot for a "full bore moderator" ...whatever that is!

+1 FOR ABOVE
no caliber just full bore on my ticket
 
i use a .25 mod on my 6.5, i took it to a rifle smith just to make sure that all the threads were straight and it all lined up ok as obviously there's not a lot of space around the bullet. He checked it out, gave it the all clear and off i went with some peace of mind.
 
i use a .25 mod on my 6.5, i took it to a rifle smith just to make sure that all the threads were straight and it all lined up ok as obviously there's not a lot of space around the bullet. He checked it out, gave it the all clear and off i went with some peace of mind.

Problem is that mine is technically a .25 moderator (it has a 6.5mm bore which is .255") you dont want to find out the hard way.
get a 7mm drill bit and put the blunt end in the end bore of the moderator.
if it goes in, you are fine, if it doesnt ......
 
Stu,

My mod is an ASE Northstar. I was advised to get the .30 cal model for my 6.5 x 55. I use the same mod on my 7mm RM.

I originally had two slots for moderators (one for swede and other for RM). I explained that I only use one mod. My FLO altered by ticket so I now have one mod that isn't specific to either rifle. This freed up a spare slot, on which is now a .22 - 250.

Cheers,

Bob
 
Yes I also have a northstar to go on the 6.5 that's the prob do I get a bigger mod! Or not!!
And at the price of them also! Seeing as this one has been on the 243 and only done 150rds
Cheers,
 
Stu,

I suggest this is such a fundamental issue of safety its probably best to seek your own advice from a suitably experienced rifle smith. I certainly wouldn't want to say "you'll be fine" only for you to use the mod and do yourself or someone else an injury.

I'm not sure who to suggest in Wilts, but I know that Mike Norris from Brock and Norris has experience with Northstars. It may be worth seeking advice from him or another.

Cheers,

Bob
 
its a fundamental issue of physics.
a 6.5mm bullet needs a minimum 7mm hole to go through to give a sensible tolerance.
 
I've seen a thread on SD about this. I think you will need a .30 cal CF mod for 6.5x55, the reason for this is that the heavier and longer 6.5 bullets yaw slightly as they leave the end of the barrel and can tough the baffles of the mod on the way out so a .30 cal mod is recommended for 6.5, I'm sure if you gave Jackson's a ring they will help you out.

Jase
 
I've seen a thread on SD about this. I think you will need a .30 cal CF mod for 6.5x55, the reason for this is that the heavier and longer 6.5 bullets yaw slightly as they leave the end of the barrel and can tough the baffles of the mod on the way out so a .30 cal mod is recommended for 6.5, I'm sure if you gave Jackson's a ring they will help you out.

Jase

Hmmm I cannot see that unless the muzzle of the barrel is badly worn/erroded or the crown very uneven. Yaw would not show up quite that quickly. The other thing is that other calibres also use long heavy for calibre bullets yet I see no mention of those having this "supposed" problem.

Due to a mix up the Moderator I brought was a .243 one and not as we first thought a .30 cal one. However after talking to the Makers and doing some of my own checking it proved fine not only on the .243 but the 25-06 and 6.5x55 as well.


I suggest the OP contacts the makers of the moderator and asks them ;).
 
Brithunter
If the OP contacts the makers and gets an answer, what will we all do on the forum?
You seem like one of those strange people who read the instructions!

:D:D
 
Jason, I'm not sure where the yaw theory came from, but it doesn't work. The bullet is travelling at 2500fps, and spinning at several thousand revolutions per minute. The gyroscopic stability is impressive with those kind of figures.

A badly corroded crown might possibly impart a tiny bit of yaw, but not enough to worry about.

The bullet diameter is .264", leaving 18 thou either side for a 30 cal moderator, assuming that the hole diameter is exactly to .3".

The original question was can I use a .25 cal moderator. The 6.5 bullet diameter is .264", a .25 cal bullet has a diameter of .255". Assuming the mod hole is slightly larger than the .255", you may well be cutting it very fine, if indeed you have a clearance hole at all.
 
Thankyou all for your replys! This might sound silly but I have just tired putting the 7mm drill in and no probs also git a 6.5 bullet and dropped it in and thus has Clearence also!
 
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