suppressed energy vs. full loads

[RPB]

So the dilema is trying to figure out how much my dads night vision scope will hold up to. I can get a brand and model next time I see him.

Currently he is running it on his AR chambered in .223 no big deal right, shooting a 70 grain pill at about 2800.

He is making short work of the hog population in the river bottom and is getting another gun. He is going the suppressed route but wants the most knock down energy available. His choice was the 458 socom. nice rig to say the least, (he is more of a reloader guru than a hunter and for some reason wanted this gun) anyhow, the 458 loaded with a 500-600 grain pill suppressed packs a pretty good thump down range.

Question is? does the ending down range energy of two rounds being equal have the same starting energy in the chamber?

Just an example, pay no attention to the numbers cause they are wrong.

.223 at 2800 fps 70 grn pill = 500ft/pnds energy
.458 at 1000 fps 500 grn pill = 500ft/pnds energy

do they both have the same starting forces, is the reaction in the chamber the same, is the action going to cycle with the same force for both rounds.

50,000psi case pressuer on the 223 is a lot more then 35,000 for the 458 wouldnt that be not as big a bang?

Asking these questions because he was told that the night vision wont hold up to the 458. said the tube coating would come off. ok, just got the info, Morovision MV 740 Gen 3 Pinnacle Select. he was told it was not the bang but the hard hitting action that jars the scope to pieces. Said the scope would not hold up to anything hotter that a fully loaded 6.8 spc

anyone have any dealings with this matter

[Samson]

Your dad knows what hes talking about. the 458 has significantly more recoil than the .223 and would kill the D740 in no time. In fact no one will warranty the 740 for anything other than .223. ITT rates their pinnacle tubes for .223 and below. The 458s have been know to break some of the cheaper collapsible stocks. Bill Wilson put a D740 on a 458 when he was testing the round, but he has more money than he knows what to do with. I wouldn't risk it as those are 4K plus new.

[RPB]

what about the 458 round suppressed or any round for that matter that has the same energy as the 223. that is what I am asking how do you find out what is compareable. if they have equal down range energy is the starting energy the same also

Little bullet+ big bang = X thump
big bullet + little bang = X thump

If i am shooting something with the same kick as the 223 then what is the big deal?

[mesquitecountry]

I think you are trying to compare apples to oranges of energy versus felt recoil. You want to focus on felt recoil, which is the tube killer.

If the felt recoil is comparable I would say you would be correct, it wouldn't make a difference.

However the felt recoil on a 458 is substantially higher. If you want a NVG safe round with more power go to the 300 blackout in a 110 grain bullet weight and supersonic.

I had a D760 and have shot it on my 308 with no issues but only a few rounds and always suppressed.

Suppression always reduces felt recoil, in bolt guns. The gas has no choice but to move forward not backwards towards the shooter.

Semi auto, especially Direct Impingement guns like an AR can actually increase felt recoil as more gas is sent through the tube, slamming the bolt back harder. That is why there are adjustable gas blocks.

I owned a 458 SBR with a howlitzer brake for about 6 months and hated it. It was actually Tom Miller's from Spikes personal upper.




I ran a bump fire stock with it one time. I almost dropped the rifle.


I called everyone under the sun to build a suppressor for it to no avail. You could port the barrel and build a suppressor shroud but that greatly reduces the velocity and hinders your rifle useless without the can.

Does that answer your question?

[RPB]

so would felt recoil be the same then on a 223 round with 24 grains powder going 2800 as a 458 with 24 grains going 1000. Is ther a way to figure felt recoil? with an adjustable block why not just close it enough till it cycles the action. If I can keep the 500 grain bullet suppressed right around 1050 fps and just get the action to cycle using the gas block then I would suppose the felt recoil would be less, or is it the fact that you have a 500 grain bullet leaving vs a 70 grain. Is there any correlation between down range energy and felt recoil. I am having a hard time wraping my head around this.

this woudl only be an issue with the NVS I can use a different scope with regular rounds.

[kikn]

Using a suppressor reduces imo reduces the felt recoil. I low velocity round also reduces the felt recoil. I've made many subsonic rounds in various calibers and the felt recoil even from a .308 subsonic is less than a .22lr. Not to mention having a can reduces muzzle flash and helps with follow up shots with nv devices.

Don't take my word for it though find someone with a few of these toys and see for yourself. After all it is your 3rd gen nv on the line

[mesquitecountry]

Read this

http://www.chuckhawks.com/recoil_table.htm

[Silent Assassin]

Get 7-08 and be done with it and the NV will live forever, the pigs will DRT every time. You are welcome.

[Samson]

Read this
http://www.chuckhawks.com/recoil_table.htm

Since that table doesn't list the 458 socom, I ran the #s for you. Marty lists a 500gr load with 35gr of 4198 clocking in at 1050 fps. I used the average 8 lbs for rifle weight. Plug those #s in here http://www.shooterscalculator.com/recoil-calculator.php, and you get recoil velocity of 12.5 fps and a recoil energy of 19.43 ftlbs . Compare it to that table Travis posted and you are very close to the .270 win #s. You are over double that of the .223 . You would lose a little of the recoil if running suppressed if you have an adjustable gas block. But not really enough to matter in this situation. It takes a lot of energy to push those large bullets down an undersized hole. The larger the bullet, the more surface area contact it has with the barrel, and the more energy it takes to push it out the hole. That energy is transferred to the shooter in the form of recoil. If you want less recoil, use a smaller bullet.

[Mike D]

Since that table doesn't list the 458 socom, I ran the #s for you. Marty lists a 500gr load with 35gr of 4198 clocking in at 1050 fps. I used the average 8 lbs for rifle weight. Plug those #s in here http://www.shooterscalculator.com/recoil-calculator.php, and you get recoil velocity of 12.5 fps and a recoil energy of 19.43 ftlbs . Compare it to that table Travis posted and you are very close to the .270 win #s. You are over double that of the .223 . You would lose a little of the recoil if running suppressed if you have an adjustable gas block. But not really enough to matter in this situation. It takes a lot of energy to push those large bullets down an undersized hole. The larger the bullet, the more surface area contact it has with the barrel, and the more energy it takes to push it out the hole. That energy is transferred to the shooter in the form of recoil. If you want less recoil, use a smaller bullet.

This. In addition a 500 grain bullet at subsonic velocities is going to drop like a lead balloon. I know there is 3.6 MIL of drop going from my 300 BLK 110 grain supersonic to 220 grain subsonic loads.

I think you are looking at the wrong caliber for the purpose intended.

[RPB]

Ok so using that foumula should I go that route I have to down size the bullet which intern will let me use less powder to keep it sub sonic.

I was looking for the most thump while staying sub sonic, this seemed to be it because I can get it up to a 600 grain pill.

Now, throw in the night vision, and a suppressor.

Obviously this might not be an ideal round.

I want to go quiet, I could put a suppressor on a sub 223 but I am not gaining anything from it. need more thump.

In yalls experience!!!!!!!! What chambering is going to give me the most thump suppressed and still be able to use my night vision?

Thanks guy for the previous info, I will digg more when I get off work.

[Samson]

ITT wont warranty their tubes for anything over .223 if that doesn't matter to you then put it on any of the slightly larger calibers, 6.8spc. 300bo, 7.62X40WT and hope for the best . But if your unit goes bad and you send it back, they will know the reason why. That being said, why not trade off the D740 for a helmet mount PVS-14 or PVS-7 and mount an IR laser on the rifle. That's how most people are getting to use their larger caliber rifles.

[mesquitecountry]

Ok so using that foumula should I go that route I have to down size the bullet which intern will let me use less powder to keep it sub sonic.

I was looking for the most thump while staying sub sonic, this seemed to be it because I can get it up to a 600 grain pill.

Now, throw in the night vision, and a suppressor.

Obviously this might not be an ideal round.

I want to go quiet, I could put a suppressor on a sub 223 but I am not gaining anything from it. need more thump.

In yalls experience!!!!!!!! What chambering is going to give me the most thump suppressed and still be able to use my night vision?

Thanks guy for the previous info, I will digg more when I get off work.

300 BO. I've taken down elk with 110 Vmax supers at 80 yards out of a helicopter.

IMO subs are not for hunting

[jaime1982]

300 BO. I've taken down elk with 110 Vmax supers at 80 yards out of a helicopter.

IMO subs are not for hunting

Hey Mesquite, what do you think about the300blk lehigh max expansion rds that are supposed to expand and retain wt at subsonic speed and lbs power?

[mesquitecountry]

I think Mike D bought some? I have heard of them, have not seen them in action personally.

They are super expensive. Subs are still loud enough to run off animals when shot at. I'd rather put some supers on target.