With the huge interest in the plain jane 284 & 7mmSaum in F Class got me thinking if anybody was running the 30 cal based equivalents in F Class & actually finding them an advantage. You always see written that the 30 cal seems more consistent so this got me thinking is this actually the case & is the performance of the 30 cal on these cases even a match for the 7mm's with the 180gr Berger's?
Anybody shooting 30-284 or 300 SAUM in F class?
- Thread starter Fordnutter
- Start date
I think you will find a better range of high BC projectiles in the 7mm range compared to the 30 cal.
This is the reason that I have settled on the 7mm rather than 30 cal.
You will also have pressure issues in the SAUM if you try and push the heavier 30 cal high BC projectiles at 3000 fps. Basically 7mm 180gn Bergers will run at 2950 fps with medium pressure in the SAUM case. I'd suggest the 210gn 30 cal projectiles will limit you to 2750 fps or less for similar pressures.
Of course recoil is going to be higher too, so you will need to ensure your rests and action are setup appropriately to minimise the effect of recoil on the accuracy of the rifle.
This is the reason that I have settled on the 7mm rather than 30 cal.
You will also have pressure issues in the SAUM if you try and push the heavier 30 cal high BC projectiles at 3000 fps. Basically 7mm 180gn Bergers will run at 2950 fps with medium pressure in the SAUM case. I'd suggest the 210gn 30 cal projectiles will limit you to 2750 fps or less for similar pressures.
Of course recoil is going to be higher too, so you will need to ensure your rests and action are setup appropriately to minimise the effect of recoil on the accuracy of the rifle.
Hi fordnutter.
I drive a 300 SAUM in F-O and have done very well with the 210's. In fact, I have just prepared 2 more barrels for the rifle for next year and will be building a tube gun in the caliber this year using a Barnard and Elissio stock.
I find that just under 2800 fps is the top velocity without expanding the brass and primer pockets. In side by side comparison done in multiple matches this year, it runs drops equal to a 284 shooting 180's right out to 900 yards. The drop at 1000 yards is only a couple of clicks more.
I have shot against the 7mm SAUM and 7mm-300WSM's and it will prevail against them so the 30 caliber bullets give up nothing to the 7mm's. Once you get to this level of BC and velocity the driver counts more than the cartridge.
It appears to have a couple of advantages. First, the bullets appear to be more stable in the wind and hold a tighter verticle. Miss a wind call and you get an outside waterline shot. Secondly, the rifles don't need to be cleaned as often as the 7mm's. The 1 in 10 twist is slower and less critical. I can shoot an entire match over a 3 day weekend and not clean. The last relay is still shooting 'X''s at 1000 yards. Thirdly, the barrel life appears to be in the low 2000 round range or perhaps greater.
The only disadvantage I can see is the availability of brass. The Remington brass I have bought is actually very good quality but soft.
Steve
I drive a 300 SAUM in F-O and have done very well with the 210's. In fact, I have just prepared 2 more barrels for the rifle for next year and will be building a tube gun in the caliber this year using a Barnard and Elissio stock.
I find that just under 2800 fps is the top velocity without expanding the brass and primer pockets. In side by side comparison done in multiple matches this year, it runs drops equal to a 284 shooting 180's right out to 900 yards. The drop at 1000 yards is only a couple of clicks more.
I have shot against the 7mm SAUM and 7mm-300WSM's and it will prevail against them so the 30 caliber bullets give up nothing to the 7mm's. Once you get to this level of BC and velocity the driver counts more than the cartridge.
It appears to have a couple of advantages. First, the bullets appear to be more stable in the wind and hold a tighter verticle. Miss a wind call and you get an outside waterline shot. Secondly, the rifles don't need to be cleaned as often as the 7mm's. The 1 in 10 twist is slower and less critical. I can shoot an entire match over a 3 day weekend and not clean. The last relay is still shooting 'X''s at 1000 yards. Thirdly, the barrel life appears to be in the low 2000 round range or perhaps greater.
The only disadvantage I can see is the availability of brass. The Remington brass I have bought is actually very good quality but soft.
Steve
One more thing on the 30-284. It is a very accurate cartridge and the velocity is in the middle between the 308 at 2600 fps and the 300 SAUM at 2780 fops shooting 210's. If you can handle the recoil I don't see an advantage to it other than it has a standard bolt face.
However, I am looking at a 30-06 AI. This should give the same velocity as the 300 SAUM due to harder brass and you can use a standard boltface. The slightly great case capacity should be just enough to equal the 300 SAUM.
If this is the case and the accuacy was equal this could be a very good advantage because Lapua makes 30-06 brass.
Steve
However, I am looking at a 30-06 AI. This should give the same velocity as the 300 SAUM due to harder brass and you can use a standard boltface. The slightly great case capacity should be just enough to equal the 300 SAUM.
If this is the case and the accuacy was equal this could be a very good advantage because Lapua makes 30-06 brass.
Steve
Steveb said:
Drop, within reason, is not relevant in known distance shooting. B.C., velocity and accuracy are.
Steveb said:
The shooter counts, regardless. Berger 7mm Hybrids have a G7 B.C. of .345. The 210 LRBT is .320. Given the higher velocity achievable with a .284 Win, Shehane or magnum, that is a significant advantage. Only the 230 Hybrid at G7 .380 provides a real advantage over the 7mm. I shoot the 230 in .308 at ~2500 and it definitely performs well in the wind, better than the 210s in the same application. I've shot hundreds of the former and thousands of the latter.
Steveb said:
My shooting experience and ballistics do not support your statement about stability. Holding tight vertical is a load and shooting technique problem, occasionally a topography issue on some ranges.
Why would a 7mm need more cleaning than a .30? Your conclusion regarding twist is also specious. Expressing twist in terms of turns per inch when comparing different calibers can be deceiving. The better approach is to use rifling helix angle. A 9" .284 twist is 5.592° and a 10" .308 twist is 5.455°. That is a 2.5% difference, probably not enough to attribute criticality, one way or another. I know several top F-open shooters who do not clean during a match and they shoot .284 Shehane and 7mm magnums. I clean every night, whether shooting F-T/R or F-Open. It is just a preference as I have not seen it provide either an advantage or disadvantage.
The bottom line is: Given equal shooters and rifle accuracy, .30 caliber rifles have significantly more recoil than 7mm when loaded to ballistically equal outcomes. This is the primary reason that 7mm has become dominant in F-Open.
Sleepygator and Steveb,
In regard to cleaning and the ability to shoot a 3 day match (in Aus that would be around 80 to 96 shots if you use your sighters), I don't think that the twist rate has a big bearing on it.
For example, the 6mm BR can go for 100 to 200 rounds without a clean (and VERY accurate). My 308W can go at least 48 rounds without a clean. The 7mm is still too new for me to give you an opinion on it. I hope to shoot the Marathon on the 31st December (6 ranges from 300 to 900 yards), and I'll probably clean it after the first 3 ranges as it only has around 150 rounds through it at present.
6mm BRX 31" barrel with 1:8 twist
7mm SAUM 32" barrel with 1:9 twist
308W 31" barrel with 1:12 twist
And if you talk to those using 223's, they probably don't bother to clean at all. Maybe if they sell the barrel, just so it is shiny clean
I suspect it has more to do with the quality of the barrel, and how much powder you are burning along with how fast you are pushing them down the tube.
That's my two bob's worth.
In regard to cleaning and the ability to shoot a 3 day match (in Aus that would be around 80 to 96 shots if you use your sighters), I don't think that the twist rate has a big bearing on it.
For example, the 6mm BR can go for 100 to 200 rounds without a clean (and VERY accurate). My 308W can go at least 48 rounds without a clean. The 7mm is still too new for me to give you an opinion on it. I hope to shoot the Marathon on the 31st December (6 ranges from 300 to 900 yards), and I'll probably clean it after the first 3 ranges as it only has around 150 rounds through it at present.
6mm BRX 31" barrel with 1:8 twist
7mm SAUM 32" barrel with 1:9 twist
308W 31" barrel with 1:12 twist
And if you talk to those using 223's, they probably don't bother to clean at all. Maybe if they sell the barrel, just so it is shiny clean
I suspect it has more to do with the quality of the barrel, and how much powder you are burning along with how fast you are pushing them down the tube.
That's my two bob's worth.
Sleepygator
I agree about drop but it was used as an example only to suggest that the 300 SAUM is equavalent to the straight 284 which it should be when you compare the BC and velocities that both cartridges generate.
The 210 VLD, not the BT, when pointed seem to have a higher BC than .320. I am using .340 for my graphs and that seems low. I disagree that when you get this high in velocity and BC that there is a significant difference in scores. Just my experience and I have also shot thousands of rounds. We will have to agree to disagree.
Regarding stability, it was just my observations based on a lot of matches this year shooting against many 7mm's out of different cartridges shot by many different shooters. I stand by what I observed. Were my observations in error, possibly, but I saw the same thing in many locations by different shooters. BTW, I also saw the same thing in rifles shooting the 224 caliber 90 VLD.
I agree about cleaning. Could be just the individual shooters. However, most of the 7mm shooters I know are using 1 in 8" twists and this is a lot steeper angle. The powders used in the 7mm's, particularly the short magnums, are slower burning than I use and these powders have a thicker coatings on them which, in my understanding, can be the cause of serious fouling.
30 caliber recoil is harder and I don't disagree, it is just I don't mind it and doesn't bother me.
Steve
I agree about drop but it was used as an example only to suggest that the 300 SAUM is equavalent to the straight 284 which it should be when you compare the BC and velocities that both cartridges generate.
The 210 VLD, not the BT, when pointed seem to have a higher BC than .320. I am using .340 for my graphs and that seems low. I disagree that when you get this high in velocity and BC that there is a significant difference in scores. Just my experience and I have also shot thousands of rounds. We will have to agree to disagree.
Regarding stability, it was just my observations based on a lot of matches this year shooting against many 7mm's out of different cartridges shot by many different shooters. I stand by what I observed. Were my observations in error, possibly, but I saw the same thing in many locations by different shooters. BTW, I also saw the same thing in rifles shooting the 224 caliber 90 VLD.
I agree about cleaning. Could be just the individual shooters. However, most of the 7mm shooters I know are using 1 in 8" twists and this is a lot steeper angle. The powders used in the 7mm's, particularly the short magnums, are slower burning than I use and these powders have a thicker coatings on them which, in my understanding, can be the cause of serious fouling.
30 caliber recoil is harder and I don't disagree, it is just I don't mind it and doesn't bother me.
Steve
Steveb said:
Bryan Litz's empirically derived data shows .320 for the LRBT and .323 for the VLD. Not very significant. I've shot a few of both and XLD's and don't see much ballistic difference. I point, too.
Steveb said:
Deterrent coatings vary widely, depending upon manufacturer. I have not seen any study that attributes fouling to deterrent coatings. But, it could be. My experience is that the amount of fouling for a given powder can be minimized by loading near, but not over, rated working pressure.
Steveb said:
I have fired almost 7000 rounds of caliber .50 BMG through several rifle types in 17 countries. Recoil averseness is not my problem. The problem with recoil is disturbance on the bags. It may be overcome in specific matches, but over the long run will begin to tell. Regardless, I am not aware of any top-ranked F-Open shooter that shoots anything but a 7mm. But, again, there could be. However, there must be something to it when so many are shooting 7mms. These guys are always looking for an advantage. If shooting a .30 would provide that advantage, they would do it.
memilanuk
Gold $$ Contributor
Not necessarily. Currently if they want to maximize their chances to make it on the national team in most countries I know of, they need to be shooting some sort of 7mm, usually a magnum of some flavor. Much the same way people *can* shoot any bullet weight they want in U.S. Palma, but most of the people making a serious run for the Palma Team shoot 155s all the time to build familiarity. Doesn't mean there aren't better options out there.
Also... 2010 FCNC was won by a .300 WSM.
Monte,
As I said, there could be. At the current time, the evidence seems to indicate that some kind of 7mm offers the best balance. We had a guy bring his .338 Lapua to a couple matches. It was great ballistically, but seemed to wear on him after shooting ~75 rounds.
As I said, there could be. At the current time, the evidence seems to indicate that some kind of 7mm offers the best balance. We had a guy bring his .338 Lapua to a couple matches. It was great ballistically, but seemed to wear on him after shooting ~75 rounds.
I don't disagree that the 7mm seems to be the best balance, however, that was not Fordnutters question. He asked if anyone was using these calibers and I do. The rest has been my experience.
Brian seems to indicate that pointing increases the BC somewhere around 5% or slightly more. .340 is 5% more than .323 and I found that to be low from my experience.
I am not pushing the 30 caliber BTW over anything for F-Class. It is just what I found to work well for me. In fact, if I had been able to buy 7mm 180 grain bullets, a barrel, and dies last year I would be shooting a 7mm myself. However, a local gunsmith makes great 30 caliber barrels only, I could buy bullets and I had a hunting rifle in 300 SAUM so I had the dies and brass. Instead of taking over a year to get a rifle together I had it finished in a couple of weeks. It sort of fell together and worked extremely well. I just observed or was told the other things during the last year of shooting my rifle. Your experiences maybe different.
The only issue I have had was last August shooting with the Team Wookie when I mixed up my hunting rifle brass with my match rifle brass and had to pound open the bolt on the line.
Shooting a 3 day Palma match of about 45 rounds per day is not bothersome to me however I could see that it could to other people.
Steve
Brian seems to indicate that pointing increases the BC somewhere around 5% or slightly more. .340 is 5% more than .323 and I found that to be low from my experience.
I am not pushing the 30 caliber BTW over anything for F-Class. It is just what I found to work well for me. In fact, if I had been able to buy 7mm 180 grain bullets, a barrel, and dies last year I would be shooting a 7mm myself. However, a local gunsmith makes great 30 caliber barrels only, I could buy bullets and I had a hunting rifle in 300 SAUM so I had the dies and brass. Instead of taking over a year to get a rifle together I had it finished in a couple of weeks. It sort of fell together and worked extremely well. I just observed or was told the other things during the last year of shooting my rifle. Your experiences maybe different.
The only issue I have had was last August shooting with the Team Wookie when I mixed up my hunting rifle brass with my match rifle brass and had to pound open the bolt on the line.
Shooting a 3 day Palma match of about 45 rounds per day is not bothersome to me however I could see that it could to other people.
Steve
I spoke to Bryan about pointing at the 2011 Berger SW Nationals. He indicated that the relative ballistic value of pointing went down as caliber increased. I think it is because the meplat is roughly the same size, regardless of caliber. So, it reduces a greater percentage of drag as caliber decreases. Even if it did nothing for B.C., I would still point. Pointing made a significant difference in my vertical dispersion in the 600-1000 yard courses.
Pointing device
What are you guy's using to point your projies?
One idea that concerned me about pointing, is the potential to distort the shape of the projectile, as you press the tip of the projie back toward its base.
This distortion may move the ogive barrel contact point affecting OAL and seating depth.
Do you guys re-batch your projectiles after pointing, so as to maintain consistent tail to ogive lengths?
What are you guy's using to point your projies?
One idea that concerned me about pointing, is the potential to distort the shape of the projectile, as you press the tip of the projie back toward its base.
This distortion may move the ogive barrel contact point affecting OAL and seating depth.
Do you guys re-batch your projectiles after pointing, so as to maintain consistent tail to ogive lengths?
I only point enough to close the tip after trimming .005-.010". It does not distort the ogive, just forms a conical tip about .090-.0120" long. I measure bullet seating depth using the Sinclair tool and a Mitutoyo digital caliper. There is no measurable change after pointing, either in seating depth or bullets. I use the Whidden tool to point and the Hoover tool to trim.
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