Cut A Test Throat With Your New Reamer

How do you know the throat cut by your new reamer is what you ordered? You don’t, unless you take the time to cut a “test throat”–something we strongly recommend.

We take pains to ensure the throat on your custom reamer is exactly as you ordered.  Rarely however, because of mis-communication or a mistake in the shop, the throat will be off sufficiently that it has to be re-cut, the barrel set back or even replaced.  This isn’t good for either of us as it wastes time and money.  The situation can be avoided by simply cutting a test throat (short chamber) and checking the fit of your dummy round to it before fitting the barrel and test firing.

The test throat can be cut in the barrel you intend to use on the rifle, or a barrel drop of the same caliber.  Run the reamer into the barrel (or drop) to the point the shoulder has been cut–but no further.  Make up a dummy round with just enough neck tension to keep the bullet from being easily pushed back into the case.  The bullet should protrude a bit further from the neck than where you plan to shoot it.

Insert the dummy round into the short chamber and push it forward so the shoulder of the case contacts the chamber shoulder.  Withdraw the dummy and compare the bullet’s location to where you want it to be.  If it’s within what you consider reasonable limits to where you’d planned, finish chambering your barrel.

If the bullet is not where you want it to be and its location is unacceptable, do not complete the chambering process and return the reamer to us for correction.

Because they apply to the suggestion to cut a short throat, our Warranty terms are re-printed below:

“Dave Manson Precision Reamers’ products are guaranteed against defects in material and workmanship.  If you feel one of our tools does not perform as it should, please call for suggestions as to its use.  We emphasize customer service above all else and strive to provide the best possible tooling.  If a tool is not right, it will be repaired or replaced, at our option. In all cases, our liability is limited to replacement of the defective tool.”

This simply means that we stand behind our products and will repair or replace them when indicated.  We will not, however, reimburse for a ruined component if a customer has not taken reasonable steps–as described above–to ensure that our tooling meets his requirements.

Custom Reamer Design

These days it seems that more and more shooters want to design their own, special-purpose chambers and are asking us to help in the process.  We’re happy to do this and have come up with guidelines as to how it can be done.  Further, we’ve created a form which, when completed, provides all necessary information to make the tooling you’ll need.

“Instructions for Reamer Design Worksheet” appears below—as well as in the “Tool Instructions” section of our web site.  When requesting a quote/ print on a custom reamer, please send a completed copy of the form to us so we can more efficiently respond to your request.

Instructions and Reamer Design Worksheet

E-Mail and Tracking Numbers

Over the past several years, the amount of time we spend answering e-mails and providing tracking numbers has increased way out of proportion to any increase in sales.

With tracking numbers, it seems that everyone wants to plot the progress of his order during shipment.  We have no way of sending these automatically, so it has to be done manually, which takes time that could better be used otherwise.

Because of this, we will no longer provide tracking numbers unless a package is lost—which was the original purpose of tracking numbers.

As far as e-mails go, 2 or 3 used to be sufficient to settle questions regarding an order.  Over the past several years, twice as many seem to be needed to cover all the bases, and the questions/e-mails are not nearly as well thought-out as in the past.  It’s almost as if the sender has a phone in his hand, sending individual questions as they occur to him.

We’re not Twitter and can deal with more than one question at a time.  So please think through your project and ask all questions in your first communication so we can answer them more efficiently. We know there will occasionally be follow-up questions and will gladly deal with those when they arise.

Ejector/Extractor Relief on Headspace Gauges

Customers are asking more frequently for headspace gauges with ejector and/or extractor relief cuts.  While we have made gauges with these features in the past, it’s been for large orders and specific customers who usually have to meet governmental requirements.

Our standard headspace gauges don’t have these features, and, in our opinion, don’t need them.  Read on to find out why we say this.  Comments below assume both extractor and ejector are working as designed.

Extractor Relief

Our gauges are made with full-circumference rims that are no larger or thicker than the rims of the cartridge you’re shooting.  If the cartridge rim will slip under the extractor, the rim of the gauge will also.  Having a full-diameter head, our gauges will locate against the bolt face more consistently than will gauges with one-third or one-half of the head cut away.

Ejector Relief

Plunger-type ejectors seem to be the concern because fixed ejectors within the receiver don’t contact the gauge head during headspacing.  The ejector plunger does contact the gauge head and must be compressed so the gauge head may seat squarely on the bolt face.  This is exactly what happens when the rim of the gauge is hooked under the extractor and pivoted to line up with and enter the chamber.

Once released by the gunsmith after entering the chamber, the gauge is pressed against the chamber wall by the ejector.  As the action is closed, the gauge centers up against the shoulder of the chamber, which forces the gauge straight within the chamber and the gauge head against the bolt face.  If there’s more than minimum headspace, the minimum gauge may remain slightly tipped—but you know you have at least minimum headspace.  If the action won’t close on the maximum gauge, the gauge will be straight within the chamber and flat against the bolt face—and you know headspace is less than maximum.

Hope this helps in your gunsmithing work. (For a printable format see Tool Instructions/Useful Information).

Hot Summer Sale

We’re offering NEW reamers at half the original price (manufacturer overruns), plus shipping. We are also offering unclaimed reamers that have been sharpened to our standard tolerances for the cost of sharpening, plus shipping:

Manufacturer Overruns

Please note: First Come, First Served, No Returns

New 6.5-300 WBY Mag Available

We have made a limited number of finish reamers for the new 6.5-300 Weatherby Magnum. Cost $170 for solid pilot, $200 for removable pilot, shipped in a wooden box. These are specials so no price breaks but they are available for IMMEDIATE delivery.  Buy it now before they are gone!!

Solid vs Removable Pilot

Solid vs Removable Pilot—Which is Best?

Both solid and removable pilots do an equally good job–assuming proper clearance with the bore—and therein lies the problem. Solid pilots are ground to one size which is usually slightly smaller than minimum industry bore size; they will fit most commercial barrels closely enough to produce good results. Because there is less work to make a solid pilot reamer, they’re also about 25% less expensive.

Removable piloted reamers are made with a journal (spindle) on the front end that allows precision bushings of varying sizes to be fitted to the reamer. The gunsmith can then select a pilot bushing that fits the bore of a particular barrel with exactly the clearance he wishes.   Although the reamer with removable pilot costs more initially, and buying a selection of pilot bushings adds to the expense, this arrangement allows fine-tuning of the barrel/pilot fit.

Years ago, we used to sell about five solid pilot reamers for every one fitted with a removable pilot. This ratio has changed to approximately two solid for every one removable.   Firearms tooling–other than reamers–that uses pilot bushings (indicating rods, specialized form cutters, etc.) has become more popular and it makes sense to have a selection of bushings that can be used on both a chamber reamer and another piloted cutter that will be used on the same build.

In the end, your budget and needs will decide which system is “best”.