target shooting with a moderator

[JDBenelliM1]

Is it common to use a moderator when target shooting or would it affect accuracy over a shot string due to the mod getting hot?

 

 

Thanks

John

[The Gun Pimp]

Mods aren't common in target shooting as there is often a weight issue but some shooters use 'em. Yes, they can get hot!

[Shuggy]

I now do all my target shooting with a moderator. Much nicer than a muzzle brake.

 

I think that it needs to be a fairly chunky design and muzzle mounted in order to take long shot strings. After a lot of research I settled on an Ase Utra SL7. I nearly picked one from One Less Charlie and I'm sure that would have been just as good.

 

As for avoiding heat haze, I have found a perfect solution in the shape of some Nomex lined high temperature silicone tubing as used on high performance turbo systems. As a belt and braces solution I have also fitted a mirage band held on with Velcro.

 

I have got this thing too hot to touch without gloves, but it still groups well and the zero doesn't wander. One thing to bear in mind though is that I only use this for informal club competitions. It might be unhelpful if you are trying to make weight for one of the rule books.

[JDBenelliM1]

I have an Ase Utra northstar I use near the farm on vermin and when cold (single shot) it is very accurate. Only used it once when shooting groups but when it got hot the groups opened up alot so never tried again.

 

just wondered if this is common or just me!

[jcampbellsmith]

I was at a shoot last Sunday. I think at least 18 out of 22 folk used moderators. I've shot at targets at least five times this year and at each shoot more than 75% have been using moderators.

 

Regards JCS

[CZ Varminter]

I was at a shoot last Sunday. I think at least 18 out of 22 folk used moderators. I've shot at targets at least five times this year and at each shoot more than 75% have been using moderators.

Regards JCS

I was at the same shoot, and I run a Moddy. There was certainly no loss in accuracy due to the rifle in some cases!!! Isn't that right mr smith? Very nice 6mm

 

I would like to take the opportunity to say I really enjoyed the shoot, and was great to practice multiple positions, made fora very interesting day.

 

CZV

[gbal]

+1 on Shuggy's points.

Weight might be a deterent if rules apply.

Shooting next to brake is unpleasant.

Recoil never helps accuracy-mod reduces a lot-unless v heavy rifle already.

Hot? Probably more effect from hot barrel,as bullet does not contact mod,but no research /tests on mods.

Just peaceful-a hiss and a hit.

No accuracy effects-some find v slight improvements,due to gasses being less turbulent (?)

100 308 sporter shots: no mod,no thanks!

 

gbal

[JDBenelliM1]

Thanks for your comments gents.

 

Could the heating of the barrel cause the fliers as the mod 'traps' heat around the muzzle?

 

How many shots is too many and could you cause damage with a long shot string and no cooling time?

 

What would you safely shoot knowing it won't affect accuracy? I understand barrel profile and load will be a major factor. Both my TRG and T3 have varmint barrel profiles and I run both under book max powder weight.

 

Cheers

John

[gbal]

John,I don't think we really know:

 

Moderators also increase surface cooling area of metal in contact with barrel...

 

Competition 10-20 shot strings will be of concern to hot WSM load shooters in terms of barrel life....

 

Barrel heating causes progressive accuracy degeneration (and reduced life) but the mod is not a major factor...it's already happening....

 

Competition string shooters will have data on accuracy effects.... though without mods,typically....

 

Five shots in 15 secs from 223 has no discernible 100y effects....(.3)...don't feel inclined to go for 20....

 

Others may have data...

 

gbal

[Laurie]

 

Could the heating of the barrel cause the fliers as the mod 'traps' heat around the muzzle?

 

How many shots is too many and could you cause damage with a long shot string and no cooling time?

 

 

Cheers

John

 

 

The much bigger issue is hot air rising off the moddie affecting the sight picture. That's why barrel mounted mirage shields are becoming the norm in F-Class and benchrest. Warm air rising in front of the scope objective lens affects the aim even before you become aware of it as a visible mirage effect in the sight picture. That can happen after as few as three or four shots on a cold, still winter's day when there is a huge difference between the barrel surface temperature and the air above it. Moderator bodies heat faster than fat barrels and make the problems worse. The higher the scope magnification used, the bigger the problem / effect. I'm not 100% convinced that insulated covers will cure the issue completely in a long string of shots.

 

Having a moderator on doesn't seem to cause mid string POI changes - Foxing Tonite (Darren Evans) has shot record breaking 5-round 600 yard BR groups with his AI and a moderator fitted in both 308 and 6.5X47L forms - and BR shooters often shoot as fast as they work the bolt if conditions hold.

[Mattnall]

I had to make bushings to replace melted delrin ones on reflex moderators in the past.

[Laurie]

I should have said too that moderators are banned in international target shooting competitions and any domestic comps run to international rules - ie ICFRA regulations as applied to all prone disciplines. That's because moderators are illegal in some countries, or while legal, only at the end of an onerous and expensive licensing process. If the moderator gives a shooting benefit, it would therefore create a tilted playing field working against those unable to use them. At club level, it's up to the club members and local rules and their use is pretty well accepted everywhere - but I wouldn't like to say 100% as there's bound to be somebody somewhere who doesn't like them and has put a competition ban in place.

[jcampbellsmith]

I was at the same shoot, and I run a Moddy. There was certainly no loss in accuracy due to the rifle in some cases!!! Isn't that right mr smith? Very nice 6mm

 

I would like to take the opportunity to say I really enjoyed the shoot, and was great to practice multiple positions, made fora very interesting day.

 

CZV

CZV.

Thanks for the compliment. This was the first competitive outing for the 6XC built by Grant Taylor. It's an excellent rifle and the onus is now on me to perform.

Best regards

JCS

[Shuggy]

Thanks for your comments gents.

Could the heating of the barrel cause the fliers as the mod 'traps' heat around the muzzle?

How many shots is too many and could you cause damage with a long shot string and no cooling time?

What would you safely shoot knowing it won't affect accuracy? I understand barrel profile and load will be a major factor. Both my TRG and T3 have varmint barrel profiles and I run both under book max powder weight.

Cheers

John

I remember reading somewhere about the US Marine Corps trials of suppressor for the M40A5 sniper rifle programme. The USMC found that point of impact tended to shift with reflex moderators when they got hot. The reason was thought to be that the suppressors would expand at a different rate to the barrels, causing stress between the thread and the bushing.

 

This effect would have little relevance for the sporting shooter, but for target shooting, muzzle mounted suppressors are the way to go IMO.

[JDBenelliM1]

Shuggy, would the Ase Utra North Star be classed as reflex or not as it doesn't have a bush?

 

Sorry daft statement! It is a reflex mod but as it doesn't have a rear bush I assume this wouldn't cause the issue you mention?

[Shuggy]

Strictly speaking Reflex is a brand name for BR Tuote, but it's come to be generally accepted as the type that sleeves over the barrel. No rear bush though on a Northstar, so in theory getting hot shouldn't affect the groups. I'd wonder though if your thread was cut correctly?

[JDBenelliM1]

It did group vey well until it got hot. I shoot it with a muzzle break and it is accurate so would assume if the thread is off it would affect a brake aswell

 

If the thread is off would it not shoot badly all the time?

[JDBenelliM1]

Now I have done a lot more shooting with the rifle, I might try it again with the mod on to see what happens

 

Does anyone else use an AU North Star?

[JDBenelliM1]

Strictly speaking Reflex is a brand name for BR Tuote, but it's come to be generally accepted as the type that sleeves over the barrel. No rear bush though on a Northstar, so in theory getting hot shouldn't affect the groups. I'd wonder though if your thread was cut correctly?

The rifle has a thread protector, I forget the term but I think it's an invisible thread cap? This would indicate a bad thread by being slightly off but it fits perfectly

[Shuggy]

It did group vey well until it got hot. I shoot it with a muzzle break and it is accurate so would assume if the thread is off it would affect a brake aswell

If the thread is off would it not shoot badly all the time?

Probably, yes. But it could be the female thread on the moderator that is off.

[JDBenelliM1]

Good point! How could I tell if it was

[Shuggy]

You need a thread plug gauge of the right size. Time to visit you local friendly gunsmith.

[JDBenelliM1]

Thanks shuggy, good plan.

[JDBenelliM1]

Went out tonight with the mod on to take advantage of zero wind and see if I could get consistent groups at a decent range with the mod on.

 

Turns out it did pretty well and shot three groups total and they were all OK. Didn't run it too hot and let it cool while i went to inspect the target which could be the key. Best group was the second with shots 7 - 11 (shown below).

 

Didn't do more than a five shot string. Left it for 15 mins to cool between groups.

 

 

Managed to shred the paper target when I hit the gong hanging above it!

 

[Shuggy]

That's pretty good. I've found that my .308 with SL-7 moderator will still group into about 1.5" at 100 yards, even after 3 x 20 round boxes of GGG ball, shot in a continuous string. The barrel is standard Remington factory varmint.

 

What profile is your barrel?