Fieldcraft 308 subsonic rifle without suppressor questions

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Loganwade

Best regards, Logan
Full Member
Minuteman
Mar 7, 2013
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#1
Hello all,
I am getting ready to purchase a 308 rifle for shooting subsonic loads on my property. For the time being I have no plans on buying a suppressor. I have heard that a 308 even without a suppressor isn't much louder than a 22? Any body have any input on sound level? I am looking at rifles and seeing a lot that only have 20 to 22" barrels I'm concerned that the shorter barrels may make it quiet abit louder.
For 308 subsonic unsupressed loads what kind of differences in loudness should I expect n 20" 22" and 24" barrels?
 
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#3
Yes I reload, never subsonic yet so any tips there would be appreciated as well. I'm interested in trail boss of I can find it or maybe cotton in left over case space with some other fast pistol powders. Haven't finished researching yet
Thanks for input I had no idea I needed 1 in 8 twist barel
 
#4
you can still use a 10" twist barrel

yes it is still loud and you will need ear protection - i don't think there will be much if any difference with barrel lengths listed

have used Titegroup as my subsonic powder with no issues in either jacketed or cast
 
#5
supersniper said:
you can still use a 10" twist barrel

yes it is still loud and you will need ear protection - i don't think there will be much if any difference with barrel lengths listed

have used Titegroup as my subsonic powder with no issues in either jacketed or cast
Click to expand...

Thanks, I have some tightgroup. Do you enlarge your flash holes, add cotton ect for filler or lubricate your bullets?
 
#7
Gunfighter14e2 said:
Just a little less than a 5" 45acp. If you shoot a gas gun you can mod the gas system to knock the noise down to sub 25 acp levels.

FYI,...If you cast you can get to 400yds + with a lyman 311332BV using a 12 twist w/o issue.
Click to expand...

That sounds reasonable, I don't think ill bother neighbors to much. I'll be 100 yards away and shooting directly away from them in fairly thick timber. Now I just need to build a backstop.
 
#8
subsonic without a can is pointless.

Subsonic 308 without a can sounds like a handgun, maybe even slightly louder.

IMO 95% of the "noise" of a gun being shot is the shot itself. The sonic crack isnt the annoying part(well maybe if you hear the sonic crack go right over your head).

You're going to be disappointed.
 
#10
My understanding is noise from gun fire comes from three sources:

01 - Gas leaving barrel
02 - Crack of supersonic bullet
03 - Mechanical noise (like for semi-autos)

And my understanding is suppressor can help with source 01.

So it would seem that suppressor will make things quieter for people at the shooting position and behind the shooting position ... but people anywhere along the bullet path (even 60 degrees off the line of fire) would still hear the "crack" first ... and depending on the situation ... that might be the loudest thing they heard.

So certainly for effects on the shooter, the subsonic ammo might make a barely detectable difference where as the suppressor will reduce the noise for the shooter.
If OPs purpose is to reduce noise from his perception then he will probably be disappointed. But if he wishes to reduce noise for neighbors anywhere in front of his firing line it might help. I bought a box of HSM 175gr 7.62 subsonic to test and I will try it and report back. My wife (at the house) cannot even hear me shoot my 7.62 but I'll call her on the radio and tell her to go out into the yard ... then fire supersonic round ... then ask if she heard it then fire subsonic and ask if she could tell the diff. She would be about 45 degrees off the line of fire on the other side of a hill. I'll repeat the test three times ... and vary the order super/sub ...
 
#11
rjacobs said:
subsonic without a can is pointless.

Subsonic 308 without a can sounds like a handgun, maybe even slightly louder.

IMO 95% of the "noise" of a gun being shot is the shot itself. The sonic crack isnt the annoying part(well maybe if you hear the sonic crack go right over your head).

You're going to be disappointed.
Click to expand...

I may be disappointed with sound, but at any rate I'll be able to save spot on reloading 1/4 less powder per my regular loads, and cheap plated bullets not meant for over 2000ft a second. And a year or 2 down the road I probably will buy a can and I'll have experience in reloading. Being quieter is nice but a lot of it is being able to train for fclass in a simalar rifle for a lot cheaper. I don't plan on shooting subs thru my match rifles.
 
#12
Gunfighter14e2 said:
If you are going to use the same spot all the time and are worried about the noise, you can use small tires and build a very good tube about 3 ft long to shoot out of. That arrangement done correctly will knock the noise in the dirt. Remember as long as the "Suppressor" is not Attached there is no issue.
Click to expand...

Thanks, that sounds very interesting.
 
#13
wigwamitus said:
My understanding is noise from gun fire comes from three sources:

01 - Gas leaving barrel
02 - Crack of supersonic bullet
03 - Mechanical noise (like for semi-autos)

And my understanding is suppressor can help with source 01.

So it would seem that suppressor will make things quieter for people at the shooting position and behind the shooting position ... but people anywhere along the bullet path (even 60 degrees off the line of fire) would still hear the "crack" first ... and depending on the situation ... that might be the loudest thing they heard.

So certainly for effects on the shooter, the subsonic ammo might make a barely detectable difference where as the suppressor will reduce the noise for the shooter.
If OPs purpose is to reduce noise from his perception then he will probably be disappointed. But if he wishes to reduce noise for neighbors anywhere in front of his firing line it might help. I bought a box of HSM 175gr 7.62 subsonic to test and I will try it and report back. My wife (at the house) cannot even hear me shoot my 7.62 but I'll call her on the radio and tell her to go out into the yard ... then fire supersonic round ... then ask if she heard it then fire subsonic and ask if she could tell the diff. She would be about 45 degrees off the line of fire on the other side of a hill. I'll repeat the test three times ... and vary the order super/sub ...
Click to expand...

Looking forward to hearing results.
 
#15
i'm in the same boat as you, and posted a similar question a few weeks ago, found some very usefull info here http://www.snipershide.com/shooting/snipers-hide-reloading/221427-308-subsonic-load-group-sizes.html

the advanced search has a bunch of topics, but then go off track pretty quickly and they are somewhat hard to follow.

the most i got out of all of 'em it is that 100-150 Y is the best to hope for (depends on bullet and twist) for stabilization issues with "acceptable" groups. no need for using fancy schmancy bullets as the BC is almost NA considering the FPS.

looks like trailboss is the most popular powder, starting higher around 11gr and working down till there's no crack & subsonic on the chrony. others being unique, 700x, red dot, tightgroup, i'm sure there's more choices.

and as above, your not going to get super quiet report, but a heck of alot less than regular ammo. there is a guy at the local range that shoots SS loads unsuppressed, and IMO to my "naked ear" standing 50 ft away the muzzle sound seems to be somewhere between .22lr HV, but not much louder than a .38 special +p., with no crack downrange, sort of muffled and less noisy than a 12 gauge target load.

i still haven't tinkered with my SS loads, but hope to do so when the weather in my area is more suited for tinkering, plus a bottle of trailboss makes a great valentines day gift!
 
#17
Ok, went to 150yds tonight, used NVD on passive, fired 2 rounds HSM 76.2x51 175gr 2580 nominal mv. Then fired 2 rounds HSM 7.62 175gr subsonic 1090 nominal mv. Talked to wife on radio after each round. She was on back porch of house about 300 degrees off my line of fire. She didn't know the sequence of super/sub I would fire. She reported first two rounds heard well and last two rounds "much, much quieter". At the firing position I could also tell the subsonic rounds were much quieter. The subsonic ammo removes most of 2 of the 3 causes of noise from gunfire, the supersonic "crack" and the cycling of the action. Subsonic rounds turn my 7.62 AR clone into a "bolt gun". But that is fine, I don't mind cycling the rifle manually if I'm getting something for it. I was actually surprised at the difference.

Of course there is a price. The 2 supersonic rounds were 1 and 2 inches high, but note I am not setup, zeroed etc. for this ammo, tonight's test was mostly to test the sound difference between the super and sub sonic rounds. The 2 subsonic rounds were not on the paper, which means they were at least 11 inches low.
I then moved to 100yds to try to make sure I could get on the paper. I fired 1 round of super and then 1 round of sub ... wife reported first round was load, second round was quiet. In this case the sub round was 7 inches lower than the super round.

Will have to crunch some numbers, but I believe this is easily manageable out to 200 for the subsonic. Now as to "cheap bullets" ... I wouldn't know :).

Later, after I returned, upon further questioning, wife reported last two rounds were a little quieter than first 4. This made sense because as my range contracts I'm moving lower in a draw and hence the is more ground between us. Also she reported the lower volume rounds were softer sounding than the higher volume rounds.

So, I think night use of subsonic ammo out to 200 is viable with the goal of reducing the noise. Our test included perceptions from the shooting position as well as perceptions from my wife at about 600 yards distance and 60D off the bullet path, three rounds of each were fired and results were consistent. Drop is high for a 7.62 round, but I also shoot DM18A1B1, 10gr, 4000fps stuff and it is worse!
 
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#18
Excellent report, thank you for it. I am excited to try it myself. I'm atleast another month away from having a rifle and testing. As for cheap bullets I don't know either, but I have heard that round nose bullets stablize better at low velocities than hpbt's. I think its about center mass and the bullets I'm speaking of are flat points, pretty similar design as a round nose, so I'm hoping they will fair well.

Sent from my Nexus 7 using Tapatalk
 
#21
Long barrel with trail boss and a 150g bullet could probably be about and quiet as you can get really with a 308. I would probably stay away from case fillers. Trail boss gives great load density.

Shorter barrels are noticeably louder, i.e. 16 inch vs 20 inch.

As far as 308 subs I like the hornady 160ftx or the sierra 150 flat nose over trail boss. Regular primers here, standard flash hole size. Both these bullets work fine in a regular old 10 twist rifle. I have had good results with both between 10 and 11 grains charge weight in a few rifles. The 180 round nose bullets are worth a look too, but I never got better results than with the 160s and 150s. As far as accuracy I am happy at around 1.5 MOA at 100 yards. Getting less CONSISTENTLY is tough.

If you go for a faster twist like a 1/8 the 220 round noses, 220 smks, and 240 smks have worked well for me. They help to get really nice case fill too since they are so long

22lr with a long barrel and colibri or super colibri is very quiet without a suppressor.

How about a nice high end big bore air rifle? They can be pretty quiet and still put a big bullet out there.

Good idea on the tire muffler btw. That works pretty well.
 
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#22
Thanx alot for input savage110nut and redbullit. I have a Savage 11 FCNS in the works. 308 1 in 10 twist 22" sporter. I will probably start with Extreme or RMR 150gr plated and go from there. Hopefully when I go make a payment they will have some trail boss in stock. I bet a 26" 22lr rifle shooting sub's would be super quiet and fun. I have a few ruger 1022's I don't mind shooting out back at all, never got any complaints yet.

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#23
I run cast and coated 150 grain bullets with 10 grains of Trailboss out of a 308. Without a can it sounds like a 9mm carbine. Has about the same energy too not a lot of difference between a 147 and a 150 at the same speed.
 
#24
No problem LW.

Those 150 plated have shot okay for me, but never got anything spectacular from them. Usually 2 to 3 inch groups at 100. They may have a bit more in them, but i have not shot enough of them yet. Not bad for subs that are super cheap to load. They are pretty much minute of can at 100 in my rifle, so definitely will work for plinking or close varmints.


Since you have that 10 twist I would experiment with everything up to the 180 round nose. I'd leave out the long sleek supersonic bullets like the SMK.
 
#26
Interesting, lead is definitely another option and less likely to get a bullet stuck in barrel and easier to remove? Is leading a problem in sub's? I'm a bit paranoid of getting a bullet stuck, which is why I ordered another rifle, at least it won't spoil an upcoming match. I even ordered some tubbs finish bullets to polish my bore a bit, never tried it before.


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#27
I have never stuck a bullet yet lol. I have shot A LOT of jacketed subs... Fingers crossed of course, but I always just work my load from high charge to low charge. I keep the velocity up above 975 or so with jacketed, but the cast bullets can be reliably run slower and even more quietly. You can lube the jacketed projectiles if you want a little extra insurance. Some people swear by it, others say no difference.

As to leading, the cast will never be as clean as jacketed. Since you are not running a suppressor though I would not sweat it. A healthily subsonic plain base lead bullet should not give you leading problems unless your alloy is waaay too soft. Some molds have boat tails for some reason… Stay away from those and you should be fine. The boat tail in the bore gives the lead a good place to melt and coat your barrel...

Another option is simply running gas check style bullets for the subs. This will offer a nice consistent base for the bullet, eliminates fouling, and usually gets you good consistency. I don't like ever running these through a suppressor,but if that is not a consideration I'd say this would be the easiest way to go.

YET ANOTHER option is to simply powder coat the cast bullets in a little toaster oven… eliminates leading almost entirely and eliminates all the messy lubes and their smoke. They look pretty too and play well with suppressors. Harbor freight sells cheap powder coating stuff. Mix it up in a bucket, tumble them around a bit, dry, voila!

Not a fan of the lapping bullets myself… shoot the piss out of it and lap it the right way with regular bullets IHMO. i think it is just like shooting a bunch or regular rounds… basically wearing my barrel out quicker.
 
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#28
Thanks a lot for input redbullet

I think I'm going to start with some 173gr FN lead with gas checks from Moyer cast. (Lyman # 311041). Powder coating sounds interesting to try some time down the road. Do you have to cast your own a bit smaller in diameter to make up for the thickness of powder coating?

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#29
No prob. Powder coating is handy, but I only do it for suppressor use bullets. Depending on how the coating goes, I get .001 or a little over for a size increase. The good thing is that you can size the bullets after powder coating if you want to and it does not seem to damage the coating. My mold is a pretty consistent .309-.310, so i usually do not size them.

I'd say those 173 will fit the bill nicely with some trail boss.
 
#31
Fired a bit more of the 175gr subsonic ammo ... having a some trouble with my NVD, but the below shows it is possible for me to shoot a very different round and very different ranges from what I'm zeroed at and it shows the elevation required to use the 175gr(subsonic) ammo is very manageable out to 200yds. Should be manageable beyond that, probably even to 300yds, don't have to worry much about wind!

==
Attempt to calculate adjustment from 147gr ammo zero to 175gr subsonic.

Assumption: Zeroed at 325 yards with 147gr ammo.

Need to hold down 1.2 mils to hit at 50yds with 147gr ammo.

From 50yd zero need to hold up 4.7 mils to hit at 150yds with 175gr subsonic ammo.

So net need to hold up 3.5 mils to hit at 150yds with 175gr(sub) ammo.

From 50yd zero need to hold up 7.5 mils to hit at 200yds with 175(sub) ammo. So net need to hold up 6.3 mils to hit at 200yds with 175(sub) ammo.

1 mil at 150yds is 5.4 inches

1 mil at 200yds is 7.2 inches

We need to cover 25 inches of drop at 150yds. (4.7 mils) minus 1.2 is 3.5

We need to cover 54 inches of drop at 200yds. (7.5 mils) minus 1.2 is 6.3


If using 3.5x magnification. Then

holding down 1.2 mils to get to 50yds will be .42 mils down.

holding up 4.7 mils will be 1.645 mils up, minus .42 is 1.225 up for 150yds

holding up 7.5 mils will be 2.625 mils up, minus .42 is 2.205 up for 150yds.

==
2014-01-28
1400-1500
20F wind 10 mph SW
Fired 4 rounds 175gr(subsonic) switched scope to 3.5x magnification as I will be using this at night.
Results

150yds
First round POA center of bull holding 1.25 mils up, no windage. POI on orange dot 6 inch down and right from bull. This is 4 inches low and 4 inches right.

Second round holding 1.75 mils up, .5 mils left. POI 1.5 inches down and left of bull. This is within 1 MOA of the bull.

200yds
Third round holding 2.5 up .5 left. POI on green dot 3 inches high directly over the bull. This is 1.5 MOA from the bull

Fourth round holding 2.25 up .5 left. POI 2 inches low and right from bull. This is 1 MOA from the bull.

So it looks like we can do fine at 200yds with the 175(sub) ammo during the day. We will try to repeat this test tonight with the NVD.

Here is target pic



So question is why did my arithmetic not work for the 150yd initial shot? I thought I needed to hold up 1.25 mils but in reality I had to hold up 1.75 mils.

At 200yds, I had pre-calculated I needed to hold up 2.25 mils and in the event that was correct.

Why did my pre-calculated arithmetic seem to work for 200yds but not for 150yds. I'll have to redo the calculations and see if I can find an error.

==

2014-01-28
Night
10F
wind 5 mph S
Fired 2 rounds 175(sub)
Results
150yds

First round POA center mass of target, could not see bull. Was firing with IR off. Turning IR off lite up too many nearby blades of grass and I could not see target. Round impacted high right 9 inches from bull. Was holding 1.75 mils up and no windage.

Second round POA center mass of target. Holding 1.75 mils up and no windage. POI high right 9 inches from bull.

Here is target pic



Is the "collimnation" problem back again? To establish this I will have to switch lots of things around. I will need the 10x Luepold scope on the .22LR and the 20x scope on the 7.62 ... only the 10x scope can easily mount the NVD and I don't want to spend 7.62 rounds figuring out whether the NVD is off again. Good news is I did score 7 boxes of 325 rds of Federal AM222 today, price was higher than I wanted to pay 11 cents a round, but having 2275 rounds of AM22 should hold me for a year and the guy threw in 50 rounds of Remington subsonic as well, so I'll have something for pre-zeroing.
I'll have to tear down the .338LM to do the above changes, so I'll go shoot it out at 600yds one more time before I do tear it down. If I have to replace the PS22 with something new, that will also cause a major rearrangement of my one time, last time (major new item acquisition) shooting budget for this summer. I might have to give up the S&B scope I wanted :(.

==
Day
2014-01-29
0800-0900
10F
wind 10 mph SSW 250 degree with respect to bullet path for this FP.

Fired 2 rounds 175(sub) from 150yds.

Here is target pic.



Purpose of this exercise was to re-verify that holding 1.75 up and in this wind .5 left gets close to the aiming point, within 1.5 MOA in this case. I was in a hurry as I need to be working by 0900 and spotting scope fogged/froze up (not water proof) so had to hoof down to the target and back before the second round. So second round farther away that it should've been.
Anyway, before I "panic" and tear everything down, I will try again tonight with the PS22. Last night, after RTB, I realized I did not focus the NVD. I am hoping that matters and I will try that tonight. I should be able to at least see the (black on white) bull. I used to be able to and I could not last night. So that makes me think/hope the NVD was not focused. So will try again tonight.
 
#33
==Night
2014-01-29
2100-2200
30F
wind 15 mph SSW, 260 degrees from bullet path

Fired 2 rounds 175(sub) at 150yds both at 1.75 mils up and .5 mils left.

Here is target pic.



I turned the NVD focus knob but could not detect much difference in clarity except at the end points. So positioned the focus in the middle between the two points of non-clarity.
The rounds hit 7.5 inches high and 3 inches right of the (bull) POA. Unfortunately the NVD seems to have lost "collimnation" again. This is frustrating because I've only fired 6 rounds of .22LR and 10 rounds of subsonic 7.62 with it since having ATN reset the collimination. I'll contact ATN to determine next steps.
I have a new 1000 smaller tac light and my older 2000 lumen larger tac light. So I will go out and test those and see if I can get to 200 with them. I've fired the 2000 at 150yds successfully before.
On moon lite nights I can see and hit the target without light aid, other than perhaps illuminated reticle, but recent nights are not moon lite. It was pretty dark out there last night. So will revert to MK-I eyeball, Ill Ret and tac lights for night shooting until the NVD can get reset again.
 
#34
Well this is what I ended up with so far for my introduction to loading cheap subsonic 308 ammo.
Oregon Trail 170gr RN FP. Was the fastest option available at a good price. I have never used a Lyman "M" Die hopefully I made a good choice. Trail boss is scheduled for delivery on Thursday.
pumutahe.jpg

9yga3e6u.jpg
 
#36
308 subsonic rifle without suppressor questions

Thanks for input gunfighter. I would like it a lot if I could get 2 moa with my lead subs at those ranges. But I will be happy with decent accuracy at only 100 with such cheap reloads.
 
#38
OP, BTW, I've been able to hit consistently out to 325yds at night with NVD and 7.62 subs, drop profile is actually fairly close to that of .22LR over that distance. Of course windage is not an issue. So, anyway, 200yds is not a barrier, head on out to 300yds and beyond!
 
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