Ultimatum Precision U300 bolt action review: Initial impressions

I first heard of the U300 back in February when Ultimatum Precision approached me about reviewing their new, three-lug action.  Looking at the CAD drawing they provided, I was impressed and couldn’t wait to get my hands on one.  It took nearly a year, but here it is, one the of first Ultimatum Precision U300 actions that was shipped to the United States.

The U300 is made in British Columbia and features the following:

  1. 3-Lug action with 60 degree bolt throw
  2. Interchangeable floating bolt heads
  3. Remington 700 footprint
  4. Integral recoil lug
  5. External bolt stop
  6. Battery safety- the firing pin can only protrude the bolt face when the lugs are locked

While more custom Remington 700 footprint actions are emerging on the market, the U300 represents a departure from its peers.  For one, it uses a 3-lug bolt, this allows for a shorter 60 degree throw, making it somewhat unique in a market flooded with two lug actions.  Further, the bolt uses interchangeable floating bolt heads, that means you can swap the bolt head on your premium U300 action the same way Savage shooters do.

As soon as my U300 arrived, I wanted it built into a gun.  I decided to chamber this one into a 6 Creedmoor!

To complete the rifle I ordered the following from Brownells:

I’ll cover details of the build in another post, but I will say this for now- it is far easier to build a rifle on a custom action like this one than it is to work off a factory 700 action.  Simply thread and chamber the barrel, crown it, and you are good to go.

Below, find the pictures of the completed barrel tenon and crown.


This action has 1.060″x16 threads, future production models will have 1.060″x20 threads to allow the use of Savage barrels and a barrel nut system.


I finished the barrel at 27″ with a M40A1/A3 style crown.



The trigger of the U300 is held in place by a trigger hanger and screw.  The trigger is inserted into the hanger and held in place with two pins.

u300-trigger-hanger-2It swings into the bottom of the action.


And is retained by a small, 4-40 screw.  I coated mine in thread lock to prevent it from backing out.  I would have preferred to see a more traditional system with two pins passing through the sides of the receiver to attach the trigger.

Deciding on a stock for the U300 was a bit of a chore.  The U300 has a very thick tang, it reminds me of a Nesika or Defiance target style tang.  While this will certainly help eliminate receiver flex and improve accuracy, it makes installation in a traditional fiberglass stock a little awkward since the tang is protruding from the top of the stock.  I test fit the action in a series of HS and McMillan fiberglass stocks and was not happy with the way it looked.  In my opinion, a chassis installation is preferable.

I like the Accuracy International AX chassis systems.  I’ve used them since their introduction and have had excellent results.  Because of this I ordered one and discovered another problem.  While the U300 will fit in an AX chassis, it WILL NOT work with an AX style magazine system (it is a little different than the AICS mag system).  I attribute this to the inlet on the bottom of the U300 action, it is narrower at the front than a Rem 700.  This means the AI AX chassis will only work if you DON’T want to feed the rifle from a detachable magazine.

I had a Modular Driven Technologies (MDT) HS3 chassis on hand as well.  The barreled action fit, however, the firing pin, which sits much lower on this design than the factory 700, impacts the stocks and will not allow the bolt to fully open (see image below).  Yikes.


So the U300 doesn’t fit well in a traditional stock, won’t feed from an AI AX chassis and you can’t open the bolt in an MDT HS3… limiting, but not the end of the world.  This is a brand new design and these things are bound to happen.  To complete my initial review, I decided to place the rifle in the AI AX and shoot it without the magazine.


A great looking rifle, isn’t it?


I loaded up eight different 6mm Creedmoor loads using 107 SMKs over H4350.  The optic is a Nightforce 3.5-15×50 F1, great optic!

6 creed 107 smk bullets with box

All shooting was conducted prone, from a bi-pod with a rear bag at 100 yards.


The U300 shot really well!  These are the first five, 5-shot groups at 100 yards.  Not too shabby, the smallest was .430″ and the largest was .760″.  I’ll take it!


That 107 SMK is a great match in the 6 Creedmoor.  Really happy with its performance.  Don’t worry, I’ll cover the load development data from this rifle in a future post.

So what are my thoughts on the Ultimatum Precision U300 bolt action receiver?

  1. Bolt throw: the 60 degree bolt throw is fantastic.  I spend a lot of time shooting a lot of bolt guns, the shorter throw is a welcome change allowing for faster bolt manipulation and shorter throw.  Better yet, it keeps your knuckles further away from the optic so they are less likely to get scraped.
  2. Interchangeable bolt heads: the interchangeable bolt head design is fantastic.  Even if you don’t want to start off with a multi caliber rifle, you never know what you might want to build down the road.
  3. Integral lug: great feature, allows for more barrel threads and a longer barrel tenon.
  4. Scope rail: includes a mirage band.  This is a nice feature for the match shooter, I’d like to see a high quality mirage band kit offered.
  5. External bolt stop:  the external bolt stop is pretty clever.  It serves as both a bolt stop and a bolt guide.  Rather than have the bolt slide in a broached raceway, the U300 has a groove in the bolt body that aligns with the bolt stop which in turn guides the bolt.  The stop is designed so the impact of the bolt transfers to a blind pin that retains the stop.  I would prefer to see this designed where the pin isn’t blind and the bolt stop is loaded with the impact of the bolt (instead of the pin).  This would prevent the pin from bending or sheering over time.
  6. Action footprint:  the action should be refined to work better with more Remington 700 blueprint stocks and chassis.  Reducing the size of the rear tang and opening the magazine well would allow the rifle to fit better in fiberglass stocks and work with the AX magazine system.
  7. Trigger system: I don’t like rifle triggers that attach with small screws for field use guns.  I realize some match rifles use this system on their actions, however, I don’t care for it in a rifle that gets knocked around.  When and if the small, 4-40 screw that holds the trigger in place vibrates loose, the firing pin will fall and discharge the rifle if it is loaded.
  8. Supporting tools: Ultimatum should develop a port entry action wrench and bolt disassembly tool.  The first time I torqued the barrel into place I actually used a Knight’s Armament URX rail wrench that I grabbed the action’s rail with.  It worked.  After talking to Ultimatum, they suggested an adjustable wrench on the flat surfaces of the receiver.  I tried this and damaged the finish.  A high quality action like this one deserves high quality service tools.
  9. Bolt lift: the bolt lift on this U300 is stiff.  Prior to receiving this action Ultimatum Precision contacted me to advise that this will be corrected in future models.  Since the finished rifle was fairly heavy, I didn’t have any problems with the bolt lift.  UPDATE: Ultimatum now ships a redesigned bolt with less bolt lift. Click here.  

Overall, Ultimatum Precision’s U300 is off to a good start.  I think as their product continues to be refined it will start to make a place for itself on the precision rifle market.

Look for upcoming posts outlining how the rifle was built and the load data we obtained with it for the 6 Creedmoor.

To learn more about the U300, visit Ultimatum Precision’s website.

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