Frenchieboy Posted July 13, 2012 Report Share Posted July 13, 2012 There seems to be some conflicting advice on this thread that a newcomer might find confusing. Can someone please clarify the situation by saying exactly what the MINIMUM bore size through the baffles and exit plate on a centrefire moderator should be for the mod to be used in a .243 rifle SAFELY? i.e. Are there any facts and figures available regarding this issue? Quote Link to comment Share on other sites More sharing options...
al4x Posted July 13, 2012 Report Share Posted July 13, 2012 I don't think anyone publishes anything exact frenchie but there is some common sense here is what the 6mm bullet looks like in a 25cal mod and at the start of the baffles you can just see there is a sensible amount of clearance. The information is there when you buy a mod In theory the less clearance so more caliber specific the better the moderation. But then you get this sort of question come up and if you want to try it then it helps to know what the mod was marketed as and all the makers use different tollerances. Its a common sense thing really but if you have to try then 1.5-2mm clearance is what I guess I've got on the two mods when used with the correct caliber bullet Quote Link to comment Share on other sites More sharing options...
swiss.tony Posted July 13, 2012 Author Report Share Posted July 13, 2012 thanks for replys wish id never asked my mate has now got ATEC for his gun and my mod is still safe but thanks anyway for effort Quote Link to comment Share on other sites More sharing options...
al4x Posted July 13, 2012 Report Share Posted July 13, 2012 swiss you could have been fine it all depended what mod you had bought, I could have used my P8 on my .223 and purchased it for the purpose as its up to 25 cal but the one I did buy would be dangerous to use Quote Link to comment Share on other sites More sharing options...
Graham M Posted July 13, 2012 Report Share Posted July 13, 2012 Be very careful about these things as it isn't always as straightforward as it appears. A few years ago a moderator was taken in to the Birmingham Proof House to be proofed for a .308. It came back with the B'ham proof mark laser-etched on the tube and marked .308, but the actual hole in the end was only 6.5mm.....so how the hell did they proof it?? For a .243 you need a hole bigger than 8mm to allow for at least .75 mm all round clearance and a .308 needs at least 9mm as the bullet is actually 7.823mm in diameter. From what I have heard moderators are batch tested for calibre so you don't find proof marks on new ones unless they have been sent off to proof with a newly cut rifle. So if you buy a .223 calibre moderator it will only have been type proofed for that calibre and really shouldn't be used on a .308 even if the hole is enlarged to accommodate a .308 bullet. Don't take chances with your safety. G.M. Quote Link to comment Share on other sites More sharing options...
Bewsher500 Posted July 14, 2012 Report Share Posted July 14, 2012 For a .243 you need a hole bigger than 8mm to allow for at least .75 mm all round clearance You don't!!!! Apart for the fact that your maths is ****! (0.75mm on all sides would be a minimum of 7.5mm! 6mm+0.75mm+0.75mm=7.5mm!) Unless you have first hand experience of fitting various moderators to CF barrels please don't add comments. It is extremely misleading and bad advice. I have first hand experience of this calibre, this issue and have taken advice directly from one of the best custom rifle builders in the country! I have a moderator with no calibre rating with a bore of 6.5mm fitted to my .243. I have put 200 rounds through it over the last 6-8 months from Ballistic tips, soft points and round nose with no issue or marks of contact at all. 6mm bullet - 6.5mm hole minimum. it doesnt matter what the mod is "rated for", what matters is what size bloody hole has it got? how straight is your threading job? can you see the moderator down the bore when it is fitted!? if you have problems or concerns see a gunsmith (not a gun shop!) The smaller the whole the better sound reduction you will get. Talking about blast is just plain balls. ALL CF mods will be subject to "blast" whatever the calibre or bore size. If you have concerns about your mod surviving "blast" then I would get a new moderator! Quote Link to comment Share on other sites More sharing options...
Bewsher500 Posted July 14, 2012 Report Share Posted July 14, 2012 So if you buy a .223 calibre moderator it will only have been type proofed for that calibre and really shouldn't be used on a .308 even if the hole is enlarged to accommodate a .308 bullet. Why not? Based on what? Quote Link to comment Share on other sites More sharing options...
EMcC Posted July 14, 2012 Report Share Posted July 14, 2012 I have just bought a new A-Tec Maxim for my .222 The box is stamped for use up to 6.5, the next size up is for .30 As I specifically asked for, and I trust the importer Jackson Rifles, a mod for a .222 it would appear that my Mod is OK for use on calibres up to 6.5 so can be used on my .243. I have found this to be true of other Mods I have used too, not thought about or guessed, actually used. The only trouble I had recently was trying to use a .308 bullet though a Mod with a 'Bridge section' that was for a .243, even then it didn't harm me in any way and it took me a few rounds before I realised the problem. It didn't feel different, it didn't sound different and didn't recoil differently. The only difference was, that no bullets hit the target, in fact there was no sign of anything hitting the target even at 50 yards. That was when I realised there was something wrong with the rifle as I knew I wasn't that bad a shot. Quote Link to comment Share on other sites More sharing options...
Graham M Posted July 14, 2012 Report Share Posted July 14, 2012 You don't!!!! Apart for the fact that your maths is ****! (0.75mm on all sides would be a minimum of 7.5mm! 6mm+0.75mm+0.75mm=7.5mm!) Do you really need to be such and ar$e? And as for shiit maths have a look again because a .243 is @ 6.18mm NOT 6.00mm so 7.5mm would NOT give .75mm it would give a clearance of .66 either side of the bullet which is stupidly small. And could give rise to a bullet strike if the the mod worked a little loose. Not going to get into a ******* contest, because I really can't be bothered these days. G.M. Quote Link to comment Share on other sites More sharing options...
Bewsher500 Posted July 14, 2012 Report Share Posted July 14, 2012 Do you really need to be such and ar$e? And as for shiit maths have a look again because a .243 is @ 6.18mm NOT 6.00mm so 7.5mm would NOT give .75mm it would give a clearance of .66 either side of the bullet which is stupidly small. And could give rise to a bullet strike if the the mod worked a little loose. Not going to get into a ******* contest, because I really can't be bothered these days. G.M. actually its 6.172mm..... not to be rounded up if your mod is loose then all maths goes out the window. not being an ****, I just hate reading threads like this giving advice and absolute fact which is plain wrong. its nothing personal Quote Link to comment Share on other sites More sharing options...
jamie g Posted July 14, 2012 Report Share Posted July 14, 2012 It is best to speak to the maker of the mod your using here are the exit holes for the ase jet z range of mods. I got the info off one of there guys there. Bullet channels for the jet-Z family; jet-Z CQB and CQBS, 7.3mm jet-Z COMPACT .25 calibre, 7.6 mm jet-Z COMPACT .30 calibre, 8.7 mm Best Regards! Tuukka Jokinen Ase Utra sound suppressors Quote Link to comment Share on other sites More sharing options...
jamie g Posted July 14, 2012 Report Share Posted July 14, 2012 actually its 6.172mm..... not to be rounded up if your mod is loose then all maths goes out the window. not being an ****, I just hate reading threads like this giving advice and absolute fact which is plain wrong. its nothing personal Thats why I like spigot threads. If a mod did come loose. The spigot should stop the bullet hitting the baffles. Quote Link to comment Share on other sites More sharing options...
Bewsher500 Posted July 15, 2012 Report Share Posted July 15, 2012 It is best to speak to the maker of the mod your using here are the exit holes for the ase jet z range of mods. I got the info off one of there guys there. Bullet channels for the jet-Z family; jet-Z CQB and CQBS, 7.3mm jet-Z COMPACT .25 calibre, 7.6 mm jet-Z COMPACT .30 calibre, 8.7 mm Best Regards! Tuukka Jokinen Ase Utra sound suppressors which one is recommended for .270? it could easily go through the 7.6mm one Quote Link to comment Share on other sites More sharing options...
jamie g Posted July 17, 2012 Report Share Posted July 17, 2012 When I had a 270 I had the 30 cal ase compact on it. The mod was very good on the noise front. But what I was most impressed with. Was how it dampend the recoil and flip. as my 270 only had a 20 inch barrel. Quote Link to comment Share on other sites More sharing options...
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