.257 FERGUSON Hot Tamale

[Fiftydriver]

Where exactly do you get that the Scramjet is a larger case then the STW?

Lazzeronis own load data lists 73.0 gr Rl-19 under the 100 gr bullet and 77.0 gr of IMR-7828 with the same bulley for max charges and velocities in the 3730-3750 fps range.

My fireforming load uses 76.0 gr Rl-22 with the 100 gr sierra spbt and it does not even have enough pressure to blow open the case mouth. Velocity with this load in a 26.5" barrel is 2780 fps, faster then the maximum velocity Lazzeoni lists for his Scramjet in a longer 27" barrel with a slower 1-12 twist.

My top working loads were up well over 80 gr of H-1000 with velocities in the 4000 fps range.

He lists 3500 fps with the 115 gr bullets and the STW will easily hit +3700 fps with a 26" barrel with top loads of Retumbo and Rl-25.

I admit I do not have a Scramjet case to measure the case volume, but by the data he is listing, he is either using very bad chices of powders or his case is smaller in capacity compared to the STW.

As far as teh strength of Lazz brass, I have seen Warbird brass loose its primer pockets when loaded to 3500 fps using his own data that is printed on the web. I mean the primers flat out fall out of the fired case.

I have also measures 7.21 Tomahawk brass that has body wall thickensses that varied by 0.025" from one side to the other consistantly.

What loads are you two using in your 6..53 Scramjet to get these velocities?

I really want to see why Lazzeronis data is so mild compared to what you are saying about this round.

Also, if you equate case strength to its weight, you will be sorely mistaken. Case strength is about alloy composition and hardness of the case head, it has nothing to do with case weight. A case can be much lighter then another and use harder, stronger brass alloy and withstand much more pressure then a soft brass case.

This may effect case volume to a point but not strength.

Good Shooting!!!

Kirby Allen(50)

 

[Ray Meketa]

Kirby - I arrived at my conclusion that the SJ case had a larger capacity by actual measurements. The SJ weighs 303 gr empty and 401 gr full of water. The 257 STw weighs 259 gr empty and 355 gr full of water. Your arguement that Lazz uses less powder in his loads is due to the fact that he loads to a more reasonable pressure and has no relationship to the capacities of the two different cases.

I agree that more brass doesn't necessarily mean harder brass but I know several shooters that use Lazz brass in both factory and hand loads and they all praise it's strength and durability. John Lazz designed his line of cartridges with strength and reliabilty in mind. He could have made the brass thinner, resulting in more powder space, but chose the other route instead.

 

[Fiftydriver]

Cheeko,

Just weighed my 257 cases made with Remington 7mm STW brass.

Sized case weights 257.2 grains average for 10 cases.

Filled with water they weight 359.9 gr average for ten cases.

Thats 102.7 grs of water weight for the 257 STW using Remington cases. Compared to the SJ with 98 gr volume as you measured.

I may load to higher pressures then Lazzeroni but I am getting at leat 6 firings per case which tells me I am in the 65,000 psi range which is totally safe for modern bolt action rifles.

Hell some of the Wby ammo loaded by Norma is running hard into the 70,000 psi range. This is why their 300 Wby load willdrive a 180 gr pill to 3300 fps, its no because of anything else but high pressure. This is why the sme load from Rem will only hit 3200 fps because Rem is watched by the SAAMI and Norma has not limits for the propriaty Wby rounds.

Lazzeroni gets less velocity because for one thing he uses the wrong powder for his rounds. He either uses very fst powder(Rl-19) with his 85 gr load which this bullet weight is far to light for such a big case and even to fast a powder for his 100 gr load recommending IMR-7282.

WIth a 100 gr pill, anything faster then H-1000 will not produce top velocity without excessive pressures.

He chose you use the faster powders and as a result he is getting less velocity then he should be if his cases have the volume you say they do.

Then with the 115 gr load he uses much to fast a powder in IMR-7828, again, he should be using a powder inteh Rl-25 to Retumbo burn rate for top velocity and useble pressures.

But he skips these correect powders and goes to 8700 which is far to slow for such light bullet weights. It will be very consistant and probably very accurate with this powder but you will be a couple hundred fps off the top potential for a round with this cases volume.

Assuming youare correct in your measurements, and I have no reason to doubt you, then the SJ would be up there close to performance with the Banshee and the STW but only when loaded to the same pressures using the correct burn rate powder.

The huge small bore rounds are very picky about which powders work the best in them. The 25-06 and even the 257 Wby can be loaded with everything from IMR-4350 to Rl-25 and they will work reasonably well.

The much larger STW and Banshee have a very narrow burn rate where they perform to top performances.

With the 100 gr pills it with powders in the burn rate of H-1000 to Rl-25.

With the 115 gr to 120 gr bullets it is Rl-25 to H-Retumbo that provides top velocity potential with good pressures.

Sure other powders can be used, but as Lazzeroni clearly shows, his velocity potential is greatly reduced because be uses teh incorrect powder for the case volume to bore volume ratio.

Even if these three rounds have exactly the same case volume, which one is the better mouse trap for the most people.

Clearly the STW with is cheap brass, top level velocities and ease in case forming. Actually, the rifles I build generally run at 1/2 moa with virgin cold formed brass when formed correctly. And this at full power velocities.

The Banshee is a great round for sure, I admit it is a better designed case then the STW for accuracy but is requires fire forming and with a round this large that is wear on the barrel.

The SJ if it is as large as you say, is also a top performer but when Lazzeroni is charging $45 per 20 round sof brass, come on!!

Baically this case is nothing more then the STW without a belt, nothing much more. Sure he used a unique case head size jsut so he could say he did but mainly so use poor suckers would be stuck buying his brass because we would not be able to form it using other lower cost brass.

Lazzeroni is very proud of his products but frankly, his ammo is not worth the money and I know his rifles are not worth what he is asking. The best thing that happened to him was when Sako adapted the Warbird and Firebird and Savage built rifles in a couple of his short mags.

Funny thing with these was I got flooded with customers saying they were blowing primer pockets out using his load data.

The problem was Lazzeroni uses specalty sized and coated bullets to get his wonder velocities as well as using rifle barrels with very slow twists to increase velocity.

The Sako and Savage rifles used standard twists and when customers loaded standard partitions and X bullets using his load data, they were way over pressure and blowing primer pockets and on brass that runs $2.50 each, this was not making people happy.

Someday I will have to get me some SJ brass and measure it to see if it is as large as you say. I will take your word for now.

With that, Lazzeroni is using the wrong powders in his data and that is limiting his veolcity potential greatly.

Good Shooting!!!

Kirby Allen(50)

 

[Ray Meketa]

fiftydriver - I guess I missed something. I can agree that the 257 STW and 257 Tamale would give identical ballistics because they are the same cartridge. However, the 6.53 Lazz is a bigger case. It would seem to me that, everything else being equal the Lazz would give less velocity with less pressure but if loaded to the same pressure as the STW it would give higher velocities. You can't fool Mother Nature and she tells me that bigger case means more powder - more powder means higher velocity.

[ 09-12-2004: Message edited by: Cheechako ]