GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: Steelhead on June 18, 2019, 11:12:38 AM
-
I've used different configurations on my .308 Texan barrel for the last couple of years with varying results. Granted, a lot of that time I was also experimenting with bullet types, tethered, untethered, etc. Now that I have two bullets that are consistently accurate and reliable at all ranges (Arsenal 115 gr. flat nose gas check and the NOE 135 gr. flat nose boattail) I'm into working on other variables.
I've been shooting exclusively with the suppressor (original model from Hunter's Supply which is a clone of the African Air Ordinance original) lately due to me having neighbors close by. My accuracy/consistency has been excellent, but packing that darn thing around away from the bench is cumbersome. The Texan is bad enough to field carry but the added weight of the suppressor makes it next to impossible to sling and extremely front heavy.
Last Saturday when shooting at 400+ yards with Steveoh at a different ranch I removed the suppressor to see if it made a difference. Not only did my accuracy decrease, but I had more recoil as well. Not that the recoil was flinch-worthy, but I was surprised at the level it had increased and it made me think that the can hanging the barrel had more of an effect than I had previously thought on performance. I also have two of the Limbsaver 'donuts' that I have not used and the Witt's clamp on muzzle break that also hasn't been used since I got the bullet selections ironed out.
So my question now is have any of you experienced drastic changes in accuracy with addition or removal of suppressors or other devices? I'm thinking that it doesn't have as big of an affect on smaller pellet shooters but on big bores (and especially Texans with the 34" barrel) has it helped, hurt, or made any difference at all for any of you? I plan on doing my own research and I'll probably back it down to 250 yards as a barometer for results. I'm thinking 250 (and probably closer) should show any differences from barrel 'accoutrements'. Your thoughts?
-
My opinion is that adding a suppressor will either increase the accuracy a little bit or have no effect on accuracy.
I think that adding suppressors to my .177 Benjamin Discovery and .177 Maximus improved the accuracy a little bit.
Adding suppressors to my 22LR rifles sometimes helped the accuracy a little bit and sometimes there was no noticeable change in accuracy.
-
I've noticed a difference in accuracy in my Texan 45 when I take my R&L shroud off my POI does change some best I remember about 1" left and 1" high but that was before I cut 5" off the barrel and frame haven't checked it since. I'll check it an see if I get to the range this Friday.
-
Yes, Suppressors most times increase accuracy. this is well known in ultra long range tactial shooting is being used in the military by snipers.
Muzzle flash is lessened. Recoil is cut up to 30% in some cases, an accuracy is increased. I addition, due to the recoil reduction, a sniper in a target rich environment will be able to shoot heavy calibers for a much longer work day, and maintain a higher degree of accuracy by not being hammered by the blast, recoil, and most importantly flash showing his position.
So not only is initial accuracy increased, long term, high shoot count shooting is less taxing on the operator, greatly enhancing the hit on target percentages.
Strippers work by removing the gasses pushing the projectile after the bullet leaves the barrel when the barrel is initially finding its balance. Again, increasing the accuracy.
Vibration dampeners/carbon fiber and particularly some of the new bonding systems that are being used to great effect to stiffen the barrels without adding the large amount of weight such as a traditional bull barrel are having an impact in special purpose long range in theater rifles. So much so that a new one is being incorporated into iirc the US Marines new AR .308 and .265 system semi auto Sniper Systems.
The archery limbsaver type donuts as it is being called here, have been used for years by such notables as Cedric S. (Tofazfou) and Doug Noble, (Dyotat100) to enhance long range accuracy in the Talon/Dors.
A change in poi is not considered a change in accuracy. That is what the adjustments o a sighting system is for. The actual accuracy is usually, as shown above, both increased immediately, and for a longer period of time in a target rich environment once again.
-
For more on the dampening effects and what it being done to enhance accuracy in our guns, please see thread here. With explanations and member test starting at post 127.
Knife
https://www.gatewaytoairguns.org/GTA/index.php?topic=157680.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=157680.0)
-
I have noticed some POI changes with and without the suppressor, but not really a group size change. I put a Witt Machine muzzle brake on and did not really notice a change in group size, but will say the rifle is easier to shoot with suppressor on and even easier with the brake. I am still trying to sort out which bullet and combination of sizing, lube ...etc provide the best accuaracy at 200 yards. So many options and so little time!!
-
The most common POI shift is usually because there is a heavier object on the end of the barrel, causing some droop down.
But sometimes there is reflected chaotic turbulence or pressure waves that act on the bullet to deflect it. If it is consistent the shooter can resight for it but if it sideways impulse varies around from shot to shot up/down/left/right you get larger groups.
I have seen baffles positioned where a moderator shot terribly then their spacing was readjusted and the moderator settled down when the adverse resonance was eliminated.
I think the biggest reason most muzzle brakes and moderators work to improve accuracy is because they act as a type of air stripper that keeps the blast of gas from blowing around the bullet as it leaves the muzzle and destabilizing it.
Have you ever tried removing everything out of your moderator and shooting it as an empty can? Very often the gun loses a lot of accuracy because the worst effects are trapped and increased around the bullet, plus the sound moderation suffers.
I started working with tensioned barrels to improve accuracy around 40 years ago in powder burners and when carbon fiber came along tried using it to stiffen and reduce resonance / muzzle flip about 15 years ago. Since I've switched completely to pneumatics for the Chalange I've discovered lighter, stiffer barrels still assist accuracy but have found that gas flow as the bullet exits the muzzle is even more critical than the PB guns. Way complex and not intuitive at all, which is why there are mostly cr@p moderators out there but 'progress stagers along' and it is getting better.
One point I would make is that powder burner gas physics inside a moderator have little to nothing to do with pneumatic moderators physics and the better airgun moderators are not following in the footsteps of the successful firearms ones. Our bullets are SLOW and while the firearm bullet has 'left the building' before the reflected gas can impinge on the bullet, a good air rifle moderator HAS to be designed to divert and keep the air/gas moving correctly for a long time, relatively.
Moderator design is not just about sound.
-
Well written Carl! 8)
Knife
-
My opinion is that adding a suppressor will either increase the accuracy a little bit or have no effect on accuracy.
I think that adding suppressors to my .177 Benjamin Discovery and .177 Maximus improved the accuracy a little bit.
Adding suppressors to my 22LR rifles sometimes helped the accuracy a little bit and sometimes there was no noticeable change in accuracy.
Please note:
When I say "increase the accuracy", this means that my 10 shot group is smaller.
The point of impact usually changes when a suppressor is added.
-
I read that section of posts that Knife referred to about the "DeadHammerCounterbalanceDeharmonizingStabilizer" mentioned in a previous post. I have done virtually the same thing by copying that recipe of JB Weld Weaver mount on the suppressor, 1" PVC, motor oil, #4 lead shot, and spray-on bedliner. No need to reinvent the wheel, especially when one doesn't even know if the wheel works. I had intended to make four of these things with different weights & lengths. I ended up completing two because I used up the 48" remnant I had by making six of them and gluing caps to one end on all before I realized my folly (math was never my strong suit) Eight caps for six tubes. Oh well...ain't the first return trip to the hardware store and won't be the last either.
If you do this yourself be aware that if using 1" PVC and 1" scope rings you will definitely need to get longer screws for the rings as the OD of the pipe is a little big. I used a little recipe for the lead shot using tablespoons for unit of measure. My 8" tube weighs 15.8 oz.'s and my 6.5" tube weighs 11.5 oz.'s. I plan on using these this coming Friday on my .308 Texan. I will post a report on the results.
-
Looking forward to it Kevin! 8)
Knife
-
I have 3 suppressors. A TKO, a Rocker1, and a "mystery pickle" that came with my used AA S400SL
They all a relatively equal in sound reduction give-or-take a Db or 3.
I have a 1/2-20 adapter that fits my airguns that are NOT threaded and have tried each of them on several.
My Crosman .22 Maximus HATES either of them. Groups open from the unsurpressed 1/4" to over 1-1/2" at 30 yards. Trust me, I have tried all 3 several times.
Other than a POI adjustment, they do not effect accuracy on any other of my guns I have tried them on.
But Maxine HATES to be stifled.... I have inquired here in the past on it, and I honestly believe it is harmonics issue.
So I have resolved to let her be as loud as she wants and we are shooting well together.
-
I've got a couple of rifles like that, they just hate anything on the barrel, moderator, stripper or brake.
Countered by those that seem to settle down.
I have a FLEX .25 with a tensioned 24" barrel that shoots 2" groups at 100 yards (38gr to 50gr slugs) unmoderated but when I put on the Ramus Technology Trident moderator the groups shrink to 1"! 50%!
Just to see if it was the weight I lathed a donut shaped weight out of brass to screw on the muzzle tension but that equaled the weight of the Trident but the groups stayed the larger size... it's not barrel resonance or the weight, the moderator helps 'somehow'.
I have a .25 Marauder with a threaded barrel end and it too shoots slightly tighter groups with the same moderator, with POI change of course.
-
I believe the Ramus Trident have an air stripper built into the LDC which would make sense!
-
Have to wait on the results of the 'device'. First thing that happened this morning was the Weaver mount popping off before I even put the suppressor on the gun ;D JB Weld stuck great to the mount, but since I had spray primered my suppressor the bond wasn't as good to the can. Oopsie. Have to scrap some paint and get to raw metal. Next time. I doubt it would have made much of a difference anyway (at least in way to observe it) as I was shooting at 400 to 500 yards the whole time. Never shot at 500 before and it's definitely a step up from 400. I was able to achieve a small level on consistency at 400 but 500 not as much. Still able to hit 2 liter bottles at 500 though and that was fun. A lot of shots, but so be it.